“Our people should become intelligent in the treatment of sickness without the aid of poisonous drugs. Many should seek to obtain the education that will enable them to combat disease in its various forms by the most simple methods. Thousands have gone down to the grave because of the use of poisonous drugs, who might have been restored to health by simple methods of treatment. Water treatments, wisely and skillfully given, may be the means of saving many lives. Let diligent study be united with careful treatments. Let prayers of faith be offered by the bedside of the sick. Let the sick be encouraged to claim the promises of God for themselves.” –Medical Ministry, p. 57

The simplest definition of hydrotherapy is “the external application of water for therapeutic purposes.”

As we learned in last month’s article, water plays an integral role in the healthy functioning of the human body. Thus, water and its unique properties can also be used as a very effective treatment for various health conditions.  Water is versatile; it can be used in all three forms in treatment: solid (ice), liquid or vapor (steam). Because water can take on many shapes and forms, water can be applied in a way that conforms to the body’s shape and contours. Our ability to float in water is useful in treatments that eliminate resistance and the pull of gravity, e.g. arthritis.

Water has conductive abilities. Conductivity is defined as a substance’s ability to transfer electricity, heat or sound via direct contact. Thermal conduction specifically refers to the transfer of heat. Heat spontaneously moves from a hotter to a colder source, when there is a difference in temperature between two substances. This movement of heat or cold takes place when the substances are in contact with one another, in other words, touching each other. Water can hold and transport a tremendous amount of heat, far more than any other substance.

Water’s conductive ability to transfer heat or cold is the reason why hydrotherapy is so successful. One of the main reasons for using hydrotherapy is to utilize the therapeutic value of heat or cold. The recuperative properties of hydrotherapy use the body’s reaction to heat and cold, by either heating or cooling the body. Water must be in direct contact with the area of the body needing to be either heated or cooled. If the water temperature is higher than the skin temperature, heat will be conducted to the skin and the temperature will rise. The opposite also applies, if the water temperature is lower than the skin temperature, heat will be removed from the skin and the temperature will decrease. For example, we can warm our hands when we hold a hot-water bottle. Or, we can cool off our body when we jump into a body of water such as a lake or pool.


The principles of hydrotherapy are applied to produce positive health outcomes for various ailments. The decision to use either hot or cold water is determined by the effect that the different temperatures have in promoting healing.

Heat applied to the body increases blood circulation, stimulates the immune system, aids digestion, and removes waste from tissues. Heat also increases blood supply to organs; blood carries germ-fighting white blood cells, nutrients, and oxygen, which aids in healing. Heat also relaxes sore, tense muscles, and aids in soothing the stiffness and pain of arthritis in the joints.

Cold water is able to lower fevers, reduce the sensitivity of painful nerve endings, decrease inflammation, slow down circulation and decongest tissues. Once cold is removed, the body reacts by opening blood vessels; tissues are flushed with fresh, oxygen-rich, nutrient-filled blood. In fact, water is more efficient in reducing fevers than any drug available.

Overall, hydrotherapy, using either hot or cold water, can be used as a sedative, for pain relief, as a laxative, an anti-spasmodic; it detoxifies, relaxes, increases or decreases muscle tone, softens connective tissue, causes numbness, produces sweating, is cleansing and acts as a stimulant. Each type of hydrotherapy treatment can be used in relieving multiple ailments. The various types of treatments and their health benefits will be discussed in more detail in next month’s article.


One goal of hydrotherapy is to improve the circulation and quality of blood and thus initiate recovery or cure. If blood circulation is poor, healing nutrients cannot be delivered and waste products and toxins cannot be removed, which causes degeneration of the tissues and organs.

Our blood transports oxygen from our lungs and nutrients from the food we eat, to all areas of our body. Blood also carries enzymes, antibodies, proteins, red and white blood cells, carbon dioxide, and waste products. The proper circulation of blood in the body is vital for this transport system to work effectively. Hydrotherapy is able to improve the circulation of the blood, thus bringing essential components to areas of the body; it promotes healing by providing life-saving blood cells and nutrients, and reduces damage by eliminating toxins and wastes efficiently.

The temperature of the blood is also important to proper functioning of organs, cells, and tissues; these can be damaged and die if temperature levels of the blood are too high or too low. The circulation system absorbs heat from the parts of the body it flows through and carries it back to the center of the body, to maintain an optimal temperature for proper organ function.

If an area of the body is too hot, the body increases blood flow to that area to carry heat away, to prevent organs from overheating. In contrast, if an area of the body is too cold, the body will prevent excess heat loss by moving blood away from that area, preventing the blood from getting too cold before it returns to the delicate organs like the heart and brain. For example, if someone is outside on a cold winter’s day, the circulation system moves blood away from the surface of the skin to prevent the skin’s contact with cold cooling down the blood that circulates to the organs.

Hydrotherapy works to control the temperature of the blood that circulates in our body, by the application of either hot or cold water, thus preventing damage from conditions that increase or decrease body temperature to unhealthy levels. Not only can hydrotherapy treatments control the overall temperature of the body, but heat or cold applied to a specific area of the body can promote healing by controlling the temperature by either moving blood to the area or moving blood away from the area. For example, an acute injury is treated with cold water, in order to decrease inflammation, and speed up recovery time.


Most hydrotherapy treatments are performed on the skin. Treatments rely on the skin’s reactions for their success. Our intact skin protects against injury, harmful chemicals, germs, and extremes of hot and cold. The skin also contains immune cells, nerve endings, and sweat glands. Skin also plays a vital role in controlling body temperature by perspiration and controlling the blood supply. This reaction of the blood vessels in the skin to heat and cold is the reason why hydrotherapy treatments used on the skin are effective in treating various health conditions.

Skin insulates the interior of the body; it is also the surface where heat is exchanged with the environment. Here the process takes place in which heat can be lost or gained. The layer of skin called the dermis contains billions of small blood vessels called capillaries. On an ongoing basis, our skin determines how much heat we lose from our bodies by either increasing or decreasing blood flow in the capillaries. This process works by either dilating (expanding) or constricting (shrinking) the size of the blood vessels. When capillaries dilate, the body loses heat; when they constrict, the body gains heat.

Controlling the flow of blood through capillaries is an important way to control the rate of heat loss or gain from our surroundings. When the surrounding temperature is colder than our body temperature 37C (98.6F), the capillaries constrict to keep heat inside the body. The opposite occurs when the temperature outside is hotter than our body temperature; the capillaries dilate to allow excess heat to leave the body. This heat gain or loss is vital, so that the body maintains its internal temperature at a level that allows the organs to function properly.

In exposure to extreme cold weather or submersion into very cold water, a condition called hypothermia occurs. This is when the body loses heat faster than it can produce heat, causing the body temperature to drop to a dangerous level. Once the body temperature falls below 35C (95F), the heart, nervous system, lungs and other organs cannot function normally.  Without immediate treatment, organ failure occurs, which can lead to death. Treatment of hypothermia consists of warming the body slowly back to a normal temperature.

Hyperthermia, or overheating is the opposite. This occurs when the body gains heat faster than it can rid itself of heat, causing the body temperature to soar to dangerous levels. Hyperthermia is a term that refers to several conditions that occur when the body cannot handle the heat in one’s environment. It often results from high temperatures, combined with high humidity and strenuous physical activity. There are many levels of severity with hyperthermia, beginning with heat stress, to heat exhaustion, and finally heat stroke.

With increasing temperatures the capillaries dilate, removing heat from the body. Another very efficient way that the body has of cooling itself is a process known as perspiration or sweating. Sweat glands are 20 times more efficient in decreasing body temperature than increasing blood flow to surface by the dilation of the capillaries. Perspiring releases water on to the skin, which then evaporates, thus cooling the body. Sweating, combined with dilation of the capillaries, prevents overheating. Heat stress begins to occur when your body is unable to reduce its temperature by sweating. Perspiration allows the body to cool down, but it also removes water from the body, which can lead to dehydration.

If the initial symptoms of overheating are not treated, symptoms worsen, which can eventually lead to heat stroke and death. Treatment of hyperthermia includes moving to a cooler area, resting and drinking water or fluids with electrolytes to restore the body’s temperature balance.

Although hyperthermia and hypothermia are reactions to extremes of temperature that can be fatal, the appropriate application of hot and cold water onto the skin can provide beneficial effects to the body. The greater the difference in temperature between the water and skin, the more intense the reaction is.


Our body contains both a central nervous system and a peripheral nervous system. Overall, the nervous system coordinates the actions of our body by transmitting signals to and from different parts of the body. The central nervous system consists of our brain and spinal cord. Our brain is the control center of our body. It receives and processes information from sensory organs, and tells the body how to respond. Messages are also received from the blood; the brain functions to adjust the amount of blood pumped from the heart, and how hard it pumps. In this way the brain can control the temperature of the blood by the amount being circulated. A part of brain called the hypothalamus constantly monitors the body’s temperature. If blood flow is above or below 37C (the ideal), it will adjust the temperature of the blood by either dilating blood vessels, which cools the body, or by constricting blood vessels, which will preserve heat. The hypothalamus also triggers the body to perspire in order to increase cooling. The spinal cord carries information between the brain and the rest of the body.

The network of nerves originating from the spinal cord connects the central nervous system to the whole rest of the body, and is known as the peripheral nervous system. Every part of our body is connected to our brain through the peripheral nervous system, a collection of nerves that influence every part of our body, including our skin, organs, muscles, and joints.

Hydrotherapy treatments on the skin also affect the nerves that are located underneath the skin; its ability to work is because all areas of the skin and the organs directly underneath that same area of skin receive messages from nerves located in the same area of the spinal cord. A “reflex effect” refers to a response that is reflected from the skin, along the nerve underneath the skin to another part of the body. Heat and cold applied to the skin can “reflexively” influence the organs underneath the skin.

For example, heat to one’s abdominal area can sooth the muscles in the area, but can also influence the stomach underneath. Some internal organs are more distantly connected reflexively to certain skin areas, for example, the skin on the feet are reflexively connected to the brain. This connection explains why hot foot soaks can dilate the vessels of the brain to relieve migraine headaches. Identical areas on opposite sides of the body also receive messages from the same area of the spinal cord. Heating the left foot can dilate vessels in one’s right foot. This is useful when a certain area of the body cannot tolerate direct heat, but would benefit from heat as a treatment.

Thus, the application of water of varying temperatures to the skin’s surface not only has a local effect, but also an effect on the cardiovascular system and other organs.

Ellen White received messages from God regarding the use of water for overall health. “Scrupulous cleanliness is essential to both physical and mental health. Impurities are constantly thrown off from the body through the skin. Its millions of pores are quickly clogged unless kept clean by frequent bathing, and the impurities which should pass off through the skin become an additional burden to the other eliminating organs.

“Most persons would receive benefit from a cool or tepid bath every day, morning or evening. Instead of increasing the liability to take cold, a bath, properly taken, fortifies against cold, because it improves the circulation; the blood is brought to the surface, and a more easy and regular flow is obtained. The mind and the body are alike invigorated. The muscles become more flexible, the intellect is made brighter. The bath is a soother of nerves. Bathing helps the bowels, the stomach, and the liver, giving health and energy to each, and it promotes digestion.” –Counsels for the Church, p. 219


Water is capable of dissolving a large number of different substances. It is known as the “universal solvent” because of water’s ability to dissolve more substances than any other liquid on earth; this property of water is important to sustain the life of every living being. Wherever water travels, either through the ground or through our bodies, it takes along valuable chemicals, minerals, and nutrients, which are essential to our wellbeing. This property of water enhances the effects of hydrotherapy by allowing medicinal substances to be dissolved in water, so that they can be absorbed into the body through the skin. Some examples are Epsom salts, oatmeal, minerals, seaweed, clay, charcoal, herbs, and essential oils. These substances can be added to one’s bath water or as part of treatments applied to specific areas of the body. We will learn more about specific hydrotherapy treatments next month.