a. The reasons for applying heat are to relieve pain, promote purulent (containing pus) drainage, increase circulation to an area, raise the body temperature, and relax muscles.

The effects of heat are to increase lymph flow, local metabolism, blood flow and blood vessel dilation, and exchange of substances through capillary walls.

b. Apply heat only according to directions of a physician or supervisor to be sure that no injury comes to the patient. Nerves in the skin are easily numbed after repeated heat application, and the patient may not feel the pain of burn. Ninety-five to 100 degrees Fahrenheit is considered warm, while 100 to 110 degrees Fahrenheit is considered hot.

If you are unsure of the correct temperature, check with the physician or supervisor. Then check with the patient to be sure the application is not too hot. Always make sure a patient can remove the heating device or move away from it if it is causing excessive discomfort. Remember that eyelids, neck, and the inside surface of arms are especially sensitive to heat.

c. Cases that require special protection from excessive heat are infants, the elderly, persons with fair skin, and patients with other disease processes present. In such cases as these, you must remain with the patient for the entire procedure and constantly monitor how well the patient is tolerating the treatment. Certain patients should be observed closely and should not be left alone while receiving therapy because they cannot tell when heat is intense. These are patients in altered levels of consciousness, paralyzed, anesthetized, with impaired circulation, and with some metabolic diseases.

d. Methods of applying heat to patients are many and varied. The old hot water bottle, now known as the warm water bag, placed in a protective cover to protect the patient from burns, is often the perfect answer to the need. The chemical hot pack is capable of excessive heat, and care must be taken to avoid serious burns. The physician’s order will dictate whether to use warm or hot moist compresses. Other methods of applying heat include soaks, sitz baths, Aqua K pack, the heat cradle, and electric heating pads.

NOTE: Do not use these methods for patients with malignant cancer, edema, or abdominal injuries unless ordered by a physician.

e. If at any time the patient complains of pain, or if you see burns, swelling, paleness, maceration (water-logged skin caused by moist heat), or redness that does not diminish with pressure, you must remove the heat treatment.