Unit 10  Heat and Cold Therapy

Chapter1 Basic Knowledge of Heat and Cold Therapy

Functions of Applying Heat and Cold

Functions of applying heat

To relieve muscle spasm The application of heat to the area for a short time can relax the muscle that is in spasm and thus dissipate the pain.

To hasten the suppuration process When heat is applied to an infected area, the increased circulation brings additional defenders against infection, that is, leukocytes (white blood cells), and takes away toxins that have been produced. The pus that is formed from these elements will consolidate in an area and may subsequently be absorbed into the circulation or drain to the outside of the body.

To hasten healing Heat applied to the body causes vasodilatation of the arterioles in the area, which remains dilated. This results in an increased blood supply to the area, bringing additional nutrients for the tissue healing.

To warm a part of the body Heat (often dry heat) is applied to warm a particularly cold part of the body. For example, a man with a leg cast may find that his foot is cold because of lack of exercise and the fact that he cannot wear a sock and shoe.

To reduce congestion in an underlying organ Heat increases blood circulation to the surface to which heat is applied, redirecting the blood from deeper congested areas.

To reduce pressure from accumulated fluid Heat increases the supply of blood to the area, and the capillaries are available for absorption of fluid. Hence, accumulated fluid is more easily absorbed into the circulation from the tissues.

To provide comfort and relaxation Heat applied to the body is comfortable and relaxing to many people. A warm tub bath relaxes the skeletal muscles and is often used to promote sleep.

Factors Affecting Heat and Cold Therapy

There are many factors affecting heat and cold applications, among these factors are mainly:

Method of heat and cold applications 

The effects of moist heat and cold are better than those of dry heat and cold, because moist heat and cold penetrate better than dry heat and cold.

Part of the body  

Cold receptors lying close to the surface of the skin are more 7 or 8 times than heat receptors, so the superficial surface of the skin is more sensitive to cold.

Size of the part of the body exposed to heat or cold 

The greater the area of the body, the lower the temperature of the heat application should be or the higher the temperature of the cold application should be.

Length of exposure to heat or cold 

. Heat or cold for a prolonged period can dilute the fuwww.med126.comnctions of heat or cold therapy and can even result in the opposed functions.

Age and condition of the patient 

Heat is less well tolerated by the very youths, the elderly, and people with circulatory problems. Elderly patients and people with impaired circulation tolerate cold worse than younger people with good circulation.

Environmental temperature  

The higher the environmental temperature is, the worse the effects of convection are. Otherwise, the lower the environmental temperature is, the better the effects of cold applications are.

Contraindications of Heat and Cold Therapy

Contraindications of heat therapy

Heat therapy should not be applied to:

● Open wounds in 24~48 hours after the trauma. Heat therapy can increase the bleeding and swelling of the trauma area.

● Any possibility of hemorrhage. Vasodilatation will increase the amount of bleeding.

● Non-inflammatory edema. Heat will increase the patient’s discomfort by increasing the blood circulation.

● An acutely inflamed area such as appendicitis. The increased blood supply could increase the inflammation and cause the appendicitis to rupture.

● A trigon around the nose. Heat therapy will result in the infection of the tissues inside the cranium.

● A localized malignant tumor. Heat therapy can promote the cancer cells to spread.

● The abdomen of a pregnant female.

Contraindications of cold therapy

Cold therapy should not be used for:

● Open wounds or the patients with impaired peripheral circulation such as a local or systemic edema.

● The patients with allergy to cold.

● A bluish, purplish appearance to the skin or mucous membrane.

● A cold feeling to the skin or mucous membrane.

● A feeling of numbness.

● Pain due to contracted muscles.

● Shivering and a lowered body temperature.

Chapter 2 Thermotherapy Applications

Thermotherapy is a therapeutic way that heat applied to surfaces increases the circulation of the blood and lymph, hastens the suppuration process, relieves muscle spasm, provides soothing comfort and speeds up the healing process.

Dry Thermotherapy

Moist applications of heat penetrate more deeply than dry heat. They tend to have a more localized effect.

Dry heat is frequently applied to the body for one or more than one reasons, such as providing comfort, drying the skin or increasing local circulation and so on. Dry heat mainly includes hot water bottles(bags), commercial hot packs, electric packs, aquathermia (water-flow) packs, heat lamps and heat cradles.

Hot water bottles (bags)  

Hot water bottles, sometimes refered to as hot water bags, are frequently used as a source of dry heat in the home. They are being used less often in hospitals because burns can result from their injudicious use, so great care must be taken not to burn the patient. The temperature of the water to be used depends on the individual condition. Those people such as the elderly, infants, young children, unconscious adults are more sensitive to heat than others, the temperature of water is less than 50℃.

Heat lamps 

Heat lamps are used to apply dry heat, usually to a small body area with an open wound. They are also used to promote healing of decubitus ulcers and the like. Two sizes of infrared lamps are commonly available, large and small. Gooseneck and infrared lamps are similar in their use and their actions.

Chapter 3  Cold Application

Cold application (Cryotherapy) is a kind of therapeutic method to use the materiwww.med126.com/sanji/als that lower the body temperature act on the local area of the body or the whole body so as to obtain the purposes of controlling bleeding, relieving pain, limiting inflammation and suppuration.

Local Dry Cold Therapy

Ice bags, ice collars, ice gloves 

The ice bag, a common device used in many homes and hospitals, is a moderate-sized rubber or plastic bag, with a removable cap, into which pieces of ice can be inserted. Commercially prepared ice bags are available in some agencies. These bags are filled with an alcohol-based solution and sealed; they are kept in freezing units in a central supply area

Local Moist Cold Therapy

Cold compresses 

Local moist cold applications are called cold compresses. They may be used for an injured eye, headache, tooth extraction, and, sometimes, for hemorrhoids. The texture and thickness of the material used depend on the area to which it is to be applied. For example, eye compresses could be prepared from surgical gauze compresses, which have a small amount of cotton filling. A washcloth makes an excellent compress for the head or the face.