Hydrotherapy

HYDROTHERAPY, or water treatment (from Greek hydor - water and therapeia - treatment), is the effect on the healthy and diseased organism of water of various temperatures and even in different states (liquid, gaseous, and solid), and in particular the systematic application of water for therapeutic and partly for prophylactic and hygienic purposes. Unlike balneology and balneotherapy, hydrotherapy deals not with mineral water in the narrower sense, but with fresh water containing only the usual small amounts of various chemical substances, and with its application not internally, but exclusively externally. The rudiments of hydrotherapy date back to the most remote times in human history. For many years, hydrotherapy was in close connection with religious beliefs and was concentrated in the hands of representatives of various cults; in later times, 'healers by natural forces' and folk healers, people little or not at all familiar with medicine (for example, teacher Ertel, peasant Priessnitz, pastor Kneipp, etc.), played a major role in this field. Initially, hydrotherapy developed mainly empirically; but it was firmly established on a scientific basis only in the second half of the 19th century, since the time of Vintherne (see), and at the present time, thanks to the works of Vintherne himself and his school (Strasser, Buxbaum), as well as many other clinicians and specialists in physiotherapy, hydrotherapy has taken an honorable place among other methods of treatment. The Russian medicine also contributed to this to no small extent through individual scientific workers and outstanding practical physicians. Foundations of water treatment. The effect of water treatment procedures in general comes down to the following three moments: thermal irritation, which plays the main role in the overwhelming majority of cases, mechanical, which is usually already additional, and finally chemical, which is carried out only in some of the mentioned procedures. As for thermal irritation, for an average healthy person and under ordinary conditions, water, due to its special physico-chemical properties (its thermal conductivity is 28 times greater than that of air, and its heat capacity is 47₂ in relation to equal weight and approximately 3,000 times in relation to equal volume), at a temperature of 34-35° is indifferent*. Such water, just like air, within the range of 20-25°, * The temperature in this article (as everywhere in the B. M. E.) is given in degrees Celsius. is not felt as either warm or cold. Therefore, when the body is affected by water of such a temperature, it remains almost at rest, or more precisely, in its previous, though relative, equilibrium. Water of any other temperature is already perceived by the body as a thermal irritation and transfers to it or removes from it a certain amount of heat, as a result of which the body is brought out of equilibrium. Due to its inherent tendency to maintain its thermal balance, numerous reflex phenomena develop in it, and all kinds of protective, compensatory, and regulatory adaptations begin to function. The character of this reaction, other conditions being equal, will depend on the irritation which the body receives from the applied hydro procedure, and the irritation itself will be determined not only by the amount of calories which are delivered to or removed from the body at that time, but also by all those features which characterize this particular hydro procedure. 1) Thus, first of all, this irritation manifests itself the more strongly the temperature of the water is lower or higher than the body temperature. Accordingly, not only the amount of the above-mentioned calories increases, but also a greater 'contrast of action' is obtained, i.e., the specific nerve endings designed to perceive heat (Ruffini bodies) or cold (Krause bulbs) are irritated more strongly. At the same time, the preliminary state of the skin coverings is of great importance; for example, a bath of indifferent temperature for a person who has been in the cold and chilled will seem warm, while for one previously overheated it will seem cold. 2) The strength of irritation increases with the suddenness of the temperature intervention; thus, when quickly immersed in a cold or hot bath, a very noticeable effect is obtained, especially - on the nervous system; but if one is placed in a bath of indifferent temperature and only then gradually increase or decrease the latter, one can even reach a large change in the bath temperature with less severe phenomena from the body; at the same time, the very character of the reaction is usually different, sometimes even opposite, especially if the irritation is unexpected. 3) The irritation will be the more pronounced the larger surface it covers, since in this case it will affect a larger number of nerve endings (approximately the same parts of the body should be compared). 4) The longer the irritation lasts, the more pronounced it is in general, although a direct proportionality is not observed; moreover, side effects can develop here, sometimes only unpleasant, and in some cases directly threatening; the entire reaction can change greatly and even become completely distorted with a long duration of the procedure. 5) An irritation of a certain strength, when repeated, gradually weakens its effect on the body: the latter adapts, as it were, gets used to it; therefore, to achieve a certain effect, the initial dose of irritation needs to be gradually increased as one gets used to it. Mechanical irritation occurs in almost all procedures, but in different forms: in showers - the jet itself already carries a significant reserve of kinetic energy (from the nozzle, water is ejected under a pressure of about 2 atmospheres); in douches and rubbings - mechanical action is added during or after the procedure itself (rubbing with the hand, glove, towel, brush); in baths - the layer of water covering the body exerts pressure (when sitting in a bath, an increase of approximately ^aDo atmospheric pressure occurs); in flow-through baths and in so-called 'Wellenbader' as well as when bathing in a river or sea, the pressure from the water flow, wave impacts, etc. is also added. This mechanical irritation, not yet sufficiently studied, undoubtedly has a certain effect on the body; for example, in a bath, peripheral vessels are compressed, the excursions of the chest during breathing decrease, and the abdominal cavity is compressed; in the shower and during rubbing - peripheral vessels expand, so strongly that it overcomes the narrowing that should occur from simultaneous or preceding cooling. In general, mechanical irritation, properly dosed and applied at the right moment, can to one degree or another contribute to obtaining the desired therapeutic effect. Thus, vigorous rubbing of a feverish patient, started from the very moment of immersing him in a cold bath, leads to the expansion of his skin capillaries. Therefore, greater heat loss by the body occurs; the latter, not feeling cold in the skin, will not intensify the combustion processes, consequently, the antipyretic effect of such a bath will be enhanced; the same rubbing reduces or even prevents the adverse consequences that could arise from the sudden and strong action of cold, namely: considerable difficulty in blood circulation due to the narrowing of peripheral vessels and the onset of too sharp a reflex from irritation of nerve endings in the skin, etc. The significance of chemical irritation in hydrotherapy, where ordinary fresh water is used, is generally insignificant, although it should be taken into account, since there are, among other things, the following facts: some people can easily distinguish soft water from hard water, and with prolonged use of the latter, many develop skin irritations; baths with distilled water have a different effect on the body compared to those with physiological solution. Many impurities, even in small quantities, have a certain effect on the resulting reaction and, depending on the properties of these substances, sometimes quite strong. Most of the substances used for this purpose (excluding volatile ones) are not absorbed through the skin, but act by 1) influencing it chemically in one way or another (irritating, calming, etc.) or 2) impregnating its upper layers, and then, upon evaporation, crystallizing in the form of tiny crystals, which then mechanically irritate and cause changes in blood circulation, evaporation; finally, 3) change the physical properties of water, for example, its heat capacity and thermal conductivity, which can also have a certain effect on the body, etc. The most common impurities are salts (especially NaCl, Na₂SO₄) and gases (CO₂, H₂S), the effect of which is more noticeable with more extensive or prolonged contact, for example, in baths, especially with repeated ones. Each of these irritations (thermal, mechanical, and chemical) can be varied (strength, duration, method of application) and dosed within certain limits. This dosage is of very great importance for the entire course of the subsequent reaction and can determine not only its strength, but also its character and even the final outcome.

For example, brief wet wraps lower body temperature, while prolonged ones cause overheating and subsequent sweating; baths at 38° are usually tolerated easily, at 40° much more difficult, and above 42° only in exceptional cases and then for the shortest possible time; a shower with strong pressure (especially a jet) stimulates, while with weaker pressure (especially a rain shower) it rather calms. Furthermore, these irritations can be combined with each other in various combinations and sequences, etc. This allows for great individualization of prescriptions; for example, in subjects who poorly tolerate temperature irritation, one can resort to procedures where mechanical or chemical irritation comes to the forefront; to promote sequential dilation of skin capillaries, rubbing is prescribed immediately after the application of cold, while to avoid or at least weaken the usual vasoconstriction caused by cold, rubbing is done simultaneously or even before its application. From such combinations over time, purely empirically, certain now very common patterns have developed—series of well-known hydroprocedures: baths, showers, douches, rubdowns (see), etc. Obviously, each of these procedures, as a known complex of specific irritations, must bear its own particular imprint of action on the body. However, by appropriately changing the details, as indicated, one can exert such a significant influence on their effect that between procedures with the same name (e.g., cold and hot baths), there will be a greater difference than between completely different ones (e.g., between warm prolonged baths and a similar rain shower). In general, the more appropriately the combination of these basic factors is selected and the more each of them is individually adapted to the given case, the more easily the procedure will be tolerated and the better therapeutic effect it will produce. The site of application of these irritations is the skin, which is not only a covering separating and protecting the body from the external environment, but at the same time a very complex in structure and important in function organ (see Skin). Hydrotherapy can, on one hand, influence the skin, and on the other—acting through it via complex reflexes and subtle interactions on the cerebrospinal and autonomic nervous system, on the endocrine glands, etc.—can exert the most diverse and more or less significant influence both on the functions of individual tissues and organs and on the vital activity of the entire organism as a whole. Various external circumstances can play a significant role in the development of the body's reaction to one or another hydrotherapeutic measure. Thus, moderate warmth of the room (about 22°) promotes sequential dilation of peripheral vessels and warming of the body, while cold hinders this; noise around, conversations, reading newspapers, an uncomfortable couch—hinder sequential rest and thereby weaken the effect of the applied procedure, etc. Therefore, attention must always be paid to these circumstances and the possibility of their influence taken into account. The most essential significance for the reaction, for its entire course and final result, is the body itself, since all processes arising in it under the influence of any irritation ultimately depend on the excitability of its individual parts, on their functional ability and on their mutual connection. Here the individual properties and characteristics of the patient with his somatic and psycho-affective attitude at the given moment will manifest. Therefore, sometimes even healthy people react quite differently to the same procedure performed under otherwise equal conditions. Even more significant in strength and character can be the deviations from the normal physiological reaction in a sick person; here, in response to the application of completely identical procedures, other, even paradoxical phenomena can already occur. The body's response to hydrotherapy can therefore be extremely diverse, and if the Arndt-Schulz law (see Arndt-Schulz law) can be applied here, it can only be with great reservations. Furthermore, the matter is complicated by the fact that reactive phenomena do not all occur at once, develop with varying strength, last for different times, and intertwine with each other. The effect of hydrotherapy on individual organs and tissues. One of the most essential aspects of the effect of hydroprocedures on the body is their effect on heat exchange. On one hand, these will be phenomena of physical regulation, namely: 1) change in the lumen of skin vessels, whereby the blood flow to the periphery is decreased or increased, and consequently heat loss is decreased (up to 70%) or increased (up to 90%); 2) increase or decrease in sweating and evaporation of sweat (to convert 1 cubic cm of water into vapor, 536.6 small calories are expended); on the other hand—3) change in respiration and heat loss through the lungs, phenomena of chemical regulation: decrease or increase in oxidation processes occurring, mainly in muscles and large glands at the expense of non-nitrogenous substances, and in case of their deficiency—at the expense of nitrogenous ones (in this case, oxidation processes can decrease only by 8-10% against the minimum, and increase by 200-300%). Any hydroprocedure with a temperature above or below 34-35° immediately sets in motion the entire complex and delicate mechanism of thermoregulation. Thus, for example, when immersing in a cold bath, peripheral vasoconstriction immediately occurs, and metabolic processes intensify (for simultaneous changes in heart activity, nervous system, respiration—see below). This will lead to limitation of heat loss and increase in heat production, i.e., a certain compensation will occur for that heat loss which will result from contact of the skin with a cooler environment or only threatens to occur, about which signals come from the periphery. Very often this compensation is so great that body temperature initially even slightly rises and only then can decrease. Ultimately, from the effect of cold, if the body's compensatory forces prove sufficient (as is the case in healthy, strong subjects and with moderate temperature and duration), body temperature remains approximately the same; while with procedures at lower temperatures and especially with greater duration, with general weakness, exhaustion, in febrile patients, where the heat balance itself is less stable, a decrease in temperature occurs. When immersing in a warm and especially hot bath, the opposite phenomena occur: dilation of the peripheral skin vessels, increased sweating, and mainly evaporation from the skin surface, decrease in oxidation processes; as a result, either maintenance of the previous temperature or, with more prolonged action of heat, conversely, a greater or lesser increase in it occurs. The latter is conditioned mainly by the fact that with dilated skin vessels, because the surrounding temperature is higher than blood temperature, the body loses less heat than it receives; that the decrease in oxidation processes can occur only to a very small extent; and finally, as soon as body temperature begins to rise, these processes also intensify. In general, cold procedures are tolerated more easily than hot ones, since, first, body tissues are less sensitive to cold than to heat (a hot bath at 45° is tolerated with great difficulty and for a short time, while with local application, hot water at 50° can very quickly cause burn phenomena, whereas cold baths at 25°, i.e., 10° below indifferent temperature, are tolerated quite easily, and with local application, water temperature can be lowered without great harm by another 10°, and even to 0°). Furthermore, the body can protect itself against a decrease in temperature much more easily than against an increase (while it is usually possible to lower temperature only by tenths of a degree and with great difficulty to one degree, except in febrile diseases where one can achieve a decrease of even 1-2 degrees, body temperature can be raised quite easily, and e.g., in a 40° bath in 30 min. an increase of approximately 3° has already been obtained). As for local procedures, obviously with them, due to the smaller surface of contact, the general effect will be significantly weaker; but since here it is possible to use higher and lower temperatures and apply them for a longer time, consequently one can also obtain a stronger local effect. However, with local application, a significant reflex effect on individual organs and parts of the body, sometimes located far from the site of application of the procedure, can occur. With local cold procedures, it is possible to achieve cooling of the underlying tissues to a greater extent and to a greater depth than warming with the application of heat [thus, with an ice pack, it was possible to achieve a decrease in temperature in the abdominal cavity by 1.0-4.0°, in the chest cavity by 3.0°, and inside the tibia even by 10°; while with a hot water pack (as much as can be tolerated) at a depth of 1-2 cm, temperature increased by 1-2°, and at a depth of 3-4 cm—only by 0.4°].

However, the local change in temperature after the application of heat lasts for whole hours, i.e., much longer than after cold. Evidently, here the character and structure of tissues (especially adipose tissue, which conducts heat and cold poorly), the condition of the vessels themselves and their vasomotors, and many other factors are of importance. Hydrotherapy has a close relationship to the metabolism in the body. In general, all procedures accompanied by cooling of the skin, especially those that result in an increase in body temperature, lead to an increase in metabolism, intensified combustion of non-nitrogenous substances; however, they have little effect on nitrogen metabolism, and the sometimes observed increased excretion of nitrogen can be explained either by the intensified washing out of the body or by improved assimilation of food; only when body temperature exceeds 39.5°C does the breakdown of protein substances occur. Thus, with hydrotherapy, extra expenditures occur in the body, which even with mild procedures can be equated to those during moderate work. To cover them, an increased supply of nutritional material is required. In addition, it is necessary to ensure an adequate supply of fluids, since both heat and cold application in the body lead to a depletion of water. At the same time, all accompanying factors should always be taken into account; for example, with mild procedures, with adequate nutrition and restriction of movement, an increase in weight can be achieved even in exhausted individuals, while with more intensive procedures, appropriate diet and increased movement can lead to weight loss even in well-nourished, obese individuals. Local hydrotherapeutic procedures can have an even greater effect on metabolism and tissue nutrition, since with them both neurotrophic influences and changes in blood and lymph circulation can be obtained to a greater degree than with general procedures. Cardiovascular system. The short-term action of moderate cold causes constriction of the skin capillaries at the site of application, followed by their dilation; however, the action of heat immediately causes their dilation; thus, in both cases, local hyperemia occurs, of an arterial character, expressed in redness of the skin and an increase in its temperature. This hyperemia is the result of irritation of both the vessel walls themselves and their nerves; at the same time, the vasoconstrictor nerves react faster, but they also tire more quickly, due to which the vasodilatory action eventually comes to the fore. With more intense or prolonged action of temperature irritation, fatigue of the vasodilators also occurs, as a result of which with cold, a slowing of blood flow occurs, i.e., venous stasis, the first sign of which is a bluish tint; with similar action of heat, dilation of vessels may also occur, but only at very high temperatures (around 45°C) or with very prolonged application, i.e., when damage to the walls begins, as the first signs of inflammatory phenomena. In the same direction as the capillaries, the small arteries as well as the veins and lymph vessels also change. As for the larger vessels and vessels located in the depth and around the site of irritation, they contract from any strong and sudden action, but from less intense action, they contract with cold and remain in this state for a long time after the peripheral vessels have already dilated, while with heat they dilate immediately (this constitutes the essential difference between hyperemia after cold and after heat). The vessels of the other parts of the skin coverings, as well as the subcutaneous tissue, muscles, and skeleton change their lumen in the same way as the skin vessels, and this is more pronounced in nearby areas as well as in symmetrically located ones. The situation is more complicated with the vessels of internal organs and cavities. In them, as most authors now recognize (Dastre-Morat law), the vessels change in the opposite direction. Exceptions are the kidneys and spleen, where the same changes occur as in the skin, and the brain, where at the beginning of the action, if sharp and sudden, constriction of vessels occurs, and later with heat they contract, while with cold they dilate. From these general rules, there can be many exceptions, especially in pathological cases—when vessel walls are altered, function of vasomotors is impaired, the organs themselves are affected, etc., as well as under certain physiological conditions. Thus, due to the nervous connection of different parts of the body, when certain areas of the skin are irritated, an influx of blood to some organs and an outflow from others often occurs; the application of local cold foot baths causes a significant influx of blood to the legs and an outflow from the head, while the application of hot ones causes an influx simultaneously to the legs and pelvic organs. The skin-vascular reaction has long been given very great importance, because experience shows that in most cases, if it is sufficiently pronounced, the overall result from hydrotherapy is favorable, especially if it is accompanied by a good nervous reaction and improvement in general well-being. Although such a relationship is by no means necessary in its entirety and for all cases, it is still always sought to obtain the skin-vascular reaction, because it clearly indicates that at least part of the reactive phenomena are proceeding in the desired direction. As for the heart itself, with cold procedures, the number of its contractions decreases, as does the amount of blood ejected with each contraction; in general, therefore, the work of the heart does not increase, although blood pressure rises slightly; with hot procedures, the number of heart contractions and the amount of ejected blood increase, and thus its work also increases, sometimes even to the point that it can be compared to that during intense physical exertions; blood pressure also increases here, as long as the heart has enough strength to push the increased amount of blood through the dilated peripheral vessels. The phenomena noted occur with both local and general temperature irritation, and so quickly that one must think that reflex phenomena play the main role here, not the direct cooling or warming of the heart. General hot baths (see) lead to a weakening of heart activity, while local hot ones, according to Hauffe, not only do not weaken, but on the contrary, strengthen and stimulate it. The addition of mechanical or chemical irritation (gases CO₂, H₂S are particularly important) to the temperature irritation further complicates and often even sharply changes the entire picture of the response reaction. Nervous system. Cold, with local and especially direct action on nerve endings or nerve trunks, lowers their excitability and conductivity, and with very strong action, even stops them, while heat, on the contrary, increases them; but, with stronger action, especially with more prolonged action, it also decreases them. However, when acting on large surfaces of the skin or on the entire skin, a much more complex and distinct influence is obtained. In general, cold procedures initially cause an unpleasant sensation of cold, chilliness, but then, if the action of cold is not too intense and brief (which is usually the case in hydrotherapy), this sensation quickly gives way to a pleasant feeling of warmth, vigor, freshness, improved well-being, and elevated mood; in the opposite case, the feeling of cold intensifies, and finally, a secondary chill occurs with a whole series of well-known unpleasant phenomena: general trembling, blueness of the lips, general weakness, etc. On the contrary, general warm procedures initially produce a pleasant sensation of warmth, which then gradually intensifies and, with more prolonged action, passes into a feeling of general calm, slight fatigue, a tendency to sleep; at the same time, a weakening of painful sensations and a decrease in spasmodic phenomena are noted. Hot procedures, after a very quickly passing appearance of trembling, goosebumps, and even actual painful sensations (such phenomena are also observed with cold procedures), have an exciting effect with very brief application, but with more prolonged application, they have a significant analgesic effect, but at the same time a strongly relaxing and tiring one. In addition, all irritations accompanied by a pleasant sensation beneficially affect the psychological state, and through it, the course of many reflexes, while unpleasant irritations have the opposite effect. Finally, as for the effect of hydrotherapy on the autonomic nervous system, it is very important (some authors see in this even the entire essence of hydrotherapy's effect on the body) and quite definite, namely: cold procedures increase the tone of the sympathetic nervous system and lower that of the vagus (a clear parallelism with the action of adrenaline), while warm procedures have the opposite effect (a great analogy with the action of pilocarpine and choline). Blood. With local and general cold procedures, an increase in the amount of Hb, the number of erythrocytes and leukocytes is noted in the peripheral blood; the specific gravity and viscosity of the blood increase, and its clotting slows down; with hot procedures, the opposite phenomena occur.

In addition, in cold weather, the sugar content in the blood increases (diabetics generally tolerate cold poorly), and in predisposed individuals (especially syphilitics, malaria patients), hemolysis of red blood cells sometimes occurs (see Hemoglobinuria). The noted changes in blood usually occur very quickly after the onset of irritation, and after cessation, they do not last long (about two hours). Most likely, they occur not so much from the effect on the blood itself and blood-forming organs, but from the redistribution of blood, from the washing out of formed elements from their accumulation sites in internal organs, from changes in the lumen of small vessels and the speed of flow in them, from changes in metabolic processes with surrounding tissues, from the formation of special substances in the skin, and from the effect on the autonomic nervous system. When using hot procedures, there may also be an influence of increased sweating, which leads to some thickening of the blood, but this is not observed in hot water baths, which is explained, among other things, by the significant entry of lymph into the blood. Regarding other properties of blood, it is still difficult to draw definite conclusions. The same can be said about changes in blood in deeper parts of the body, as well as in areas remote from the site of temperature irritation. As for the formation of protective substances in the body, under the influence of cold, it undoubtedly decreases, and under the influence of heat, it increases; at the same time, the effect of infections on the body is weakened to some degree in both cases, since cold prevents the formation of toxins, while heat promotes their neutralization by antitoxins. In general, although many experimental data and clinical observations indicate that significant cooling contributes to the onset of infectious diseases and worsens their course, still those temperature effects that are used in medicine, both cold and hot, especially when applied appropriately and methodically, can, on the contrary, be beneficial, beneficially affecting not only individual symptoms, especially those of the vascular and nervous systems, but also the febrile state in general. Muscles. The effect of hydroprocedures on the muscular system is also quite significant. In it, both blood circulation and nutrition processes change. In addition, with short-term exposure to cold, muscle strength increases, and the feeling of fatigue decreases, especially if moderate mechanical irritation is added; hot procedures, but only very short-term ones, also increase the functional capacity of muscles and reduce the feeling of fatigue, while longer-acting ones have the opposite effect, especially if they are not combined with massage. The question of the effect on smooth muscles has been studied very little, but it has been established that both cold and heat, when applied briefly, cause their contraction (especially cold); with more prolonged application, they cause relaxation (especially heat). Breathing. With sudden exposure to cold, both local (especially on the chest, face, nape) and general, the so-called 'respiratory reflex' occurs, namely: a deep breath, cessation of breathing, and a series of successive rapid and strong respiratory movements. This symptom is quite constant and can even serve as a measure of general sensitivity to cold. With general and more prolonged exposure to cold, more frequent and deeper breathing is observed, and with the effect of heat, even more frequent but also more superficial breathing. Urination. H. affects this function by 1) causing changes in the lumen of blood vessels in the kidneys (under the influence of cold, it decreases, and under heat, it increases), 2) causing fluctuations in blood pressure, 3) affecting sweating, and consequently, the entire water exchange. All these factors, when summed up, cause an increase or decrease in urine output; however, these changes in diuresis are usually not particularly significant and also pass quickly, so if fluid intake is not restricted, the amount of urine excreted in 24 hours remains almost unchanged; the same can be said about the quality of urine. Only with general water baths of indifferent temperature and lasting 1-2 hours, at least in patients with kidney disease, there is a clear increase in the amount of urine and its content of NaCl and N, i.e., signs of improvement in the secretory functions of the kidneys appear. With the effect of more intense cold, protein and even cylinders may appear in the urine; however, in healthy kidneys, these phenomena pass quite quickly, and only rarely, with a certain predisposition, more or less persistent and serious changes may develop in the kidneys. Sweating. All warm and hot, both general and local procedures, lead to increased sweating, along with all its components, with the amount reaching 1-2 liters per session. Among general procedures, general hot water baths have the strongest effect in this direction (local procedures have a much weaker effect), with sweating first appearing at the site of application, but then it more or less quickly spreads to other parts of the body, although to a lesser degree and far from uniformly. For each procedure, there is its own optimum for causing sweating; for water baths, it will be around 40°, with sweating decreasing at higher temperatures. The degree of skin hyperemia does not always correspond to the intensity of sweating; the latter depends much more on the individual characteristics of the patient and the nature of the disease, as well as a number of external circumstances. Mechanical irritation promotes sweating in the same way as sequential wrapping in warm blankets and prescribing hot drinks (tea, raspberry decoction, etc.), and sometimes 1-2 glasses of cold water. Individual characteristics of the patient and various pathological conditions have a particularly large influence on sweating, in which the tendency to it may be increased or decreased. The therapeutic value of sweating methods is quite significant, and therefore they are quite often used in practice. Application of hydrotherapy. The ultimate goal of hydrotherapy is to use for therapeutic or preventive purposes those biological processes that arise in the body under the influence of various water treatment procedures. The irritations that these procedures bring awaken dormant reserve forces in the body, more or less activate them, and contribute to self-healing. The doctor's task is to apply such measures so that their effect on the body occurs to the proper degree, to direct the resulting processes in the right direction, keep them within proper limits, and eliminate (or at least reduce) side effects. In addition to the proper combination and appropriate dosage of the main elements of H., this can also be achieved by adding to the 'main' procedure some auxiliary measures (sometimes another water treatment procedure). Among such auxiliary procedures, some, so-called 'preparatory' ones, are prescribed immediately before the main one begins. For example, wetting the face, head, and nape with cold water, which has been introduced as a general rule before any temperature intervention, especially intense, to prevent sharp fluctuations in blood circulation in the brain; then - warming the skin by one method or another (but not to sweating) before applying cold procedures to obtain a better reaction with less intense irritation. Others, so-called 'concomitant' ones, are used during the main procedure itself (for example, cold compresses on the head during hot baths, similar bucket pourings on a febrile patient in the bath, pouring from a bucket at the end of a half-bath, etc.). Finally, third ones, so-called 'concluding' ones, are used after the main one is completed; for example, wrapping in woolen blankets after various sweating procedures to enhance their effect, or, conversely, cool pourings and such baths (or half-baths) to cool the periphery, stop sweating, etc. These auxiliary procedures can be very different, but all of them must be adapted to the peculiarities of a given case and to a given procedure. Despite the fact that these auxiliary procedures are mostly simpler in technique and weaker in effect than the main one, they can often have a very significant influence on the final result of the latter. Since the reaction to any water treatment procedure lasts for a limited time, it is necessary to conduct entire 'courses of water treatment', consisting of many procedures (from 15 to 40 or more) and lasting a long time (1-2 months or more). It is impossible to determine in advance the required number of individual procedures and the duration of such a course, as this depends on a number of factors that cannot be accurately accounted for. The knowledge and experience of the doctor, as well as a comprehensive study of the patient, can undoubtedly help in this matter, but only direct careful observation during the treatment itself decides it.

Before beginning a course of hydrotherapy, it is first necessary to study the patient himself, his disease, his way of life, and the surrounding conditions, and only then should a suitable procedure be selected. It is necessary to begin with moderate irritations, and sometimes (for safety's sake) it is better to precede this with several procedures that are known to be easily tolerated (partial rubbing is most convenient), in order to thus test the reactivity of the organism, its endurance. Having carefully reached the actual dose, i.e., the appearance of the desired reaction, it is necessary to continue the treatment in this manner further, gradually, as the organism becomes accustomed, increasing the irritation. Upon achieving the goal set at the beginning of the treatment, it is useful not to immediately discontinue hydrotherapy, but to continue it for some time longer, in order to consolidate the results obtained, and sometimes even to finish the treatment with a series of strengthening or hardening procedures. Usually only one procedure is prescribed per day, and in intensive cases even only every other day; but if there are special indications for this (for example, separate, very disturbing symptoms for the patient), then sometimes 2 and even 3 procedures per day can be given, provided that this does not weaken the patient. Combinations are possible, for example: during the day a half-bath or general shower, and in the evening - a sitz or foot bath; or in the morning - rubbing, during the day - a perineal shower, and at night - a heating compress on the chest, etc. To achieve the greatest success, the patient, both during the course itself and for some time after it, must observe a certain regimen, which in general comes down to the most strict observance of the usual rules of hygiene, to a correct and calm way of life, and to sufficient and rational nutrition, as well as to observing certain special prescriptions, corresponding to the nature of the disease and the properties of the procedure used (for example, rest after hot and CO2 baths and, conversely, increased movements after a general cold shower). The mental state of the patient is also of very great importance at this time, and therefore attention should be paid to this aspect as well. Hydrotherapy can (in some cases even needs to) be combined with other methods of treatment, both physical and medicinal, and a skillfully selected combination of them can in suitable cases have the most beneficial effect on the final result of the entire treatment. Particular benefit can be derived from the prescription of a corresponding diet; sometimes it is completely necessary (for example, in the treatment of obesity). Climatic, aero-, and heliotherapy often also bring great benefit; it often turns out to be advisable to add massage, gymnastics, and electrization to hydrotherapy. Many medicinal substances can be administered simultaneously (and often with great success) both internally and under the skin. Finally, it is extremely important to also use psychotherapy in the broadest sense of this word here. The development of hydrotherapy is by no means finished, there is still much empirical and unexplained in it, but nevertheless this method of treatment, due to its simplicity, effectiveness, and easy tolerability, is finding ever greater application in almost all areas of medicine. Hydrotherapy is not only a therapeutic agent, but also a preventive and hygienic one, and one that is accessible to the broadest strata of the population. It is necessary, however, to remember that untimely or improper application of hydrotherapy can cause certain harm even in cases where it should have been more or less beneficial with its proper application.