Heat and cold application Dr. Abdul-Monim Batiha Assistant Professor Critical Care Nursing Philadelphia university

Objective Discuss the therapeutic uses of heat and cold therapy and their methods of application.

ADMINISTER HEAT AND COLD THERAPY Cells in the hypothalamus act as a thermostat to regulate body temperature. When the hypothalamic thermostat detects that the body temperature is either too high or too low, it responds systemically by instituting appropriate temperature- decreasing (vasodilation, sweating) or temperature-increasing (vasoconstriction, shivering) mechanisms to restore body temperature to the normal level.

Local responses to heat and cold occur through stimulation of temperature-sensitive receptors in the skin. Impulses travel from the periphery to the hypothalamus and the cerebral cortex. The hypothalamus then initiates heat- producing or heat-reducing reactions of the body. The conscious sensations of temperature are aroused in the cerebral cortex.

Heat and cold receptors adapt to changes in temperature. On initial exposure, receptors are strongly stimulated by extremes in temperature, but, within a short time, this response declines as the receptors adapt to the new temperature variations.

This adaptive ability of the body to temperature variations can be dangerous to clients insensitive to heat and cold extremes and may predispose them to serious injury. Nurses and clients need to understand this adaptive response when applying heat and cold.

Heat is one of the oldest nursing measures used to reduce pain and promote healing. Heat causes vasodilation and increases blood flow to the affected area, producing skin redness and warmth. Heat produces maximum vasodilation in 20 to 30 minutes; after this period, reflex vasoconstriction occurs along with tissue congestion.

Periodic removal and reapplication of heat will restore vasodilation. Prolonged exposure to heat damages epithelial cells and results in redness, tenderness, and even blister formation. The application of cold lowers the temperature of the skin and underlying tissues and causes vasoconstriction.

Vasoconstriction reduces blood flow to the affected area and produces skin pallor or a bluish discoloration and coolness. Maximum vasoconstriction is achieved at 15°C (60°F); at temperatures below 15°C, the vessels begin to dilate.

Prolonged exposure to cold results in a reflex vasodilation. Initially the skin is reddened, but later it takes on a bluish purple mottled appearance with numbness and pain because of impaired circulation and tissue ischemia.

Vasodilation and vasoconstriction of the blood vessels in the skin result primarily from increased sensitivity of the vessels to nerve stimulation but also from a protective reflex response that passes to the spinal cord and then back to the vessels.

The body’s response to the application of heat and cold is influenced by a number of factors.

The following conditions necessitate precautions in the use of heat and cold applications: Neurosensory impairment: Clients with reduced perception of sensory or painful stimuli (e.g., spinal cord injuries) are at an increased risk for tissue injury. Neurosensory impairment: Clients with reduced perception of sensory or painful stimuli (e.g., spinal cord injuries) are at an increased risk for tissue injury.

Impaired mental status: Clients who are confused or unconscious need to be monitored and assessed frequently to ensure safety. Impaired circulation: Clients with cardiovascular and peripheral vascular problems or diabetes may not have the ability to dissolve heat through dilation of blood vessels and are at an increased risk for tissue injury. Impaired circulation: Clients with cardiovascular and peripheral vascular problems or diabetes may not have the ability to dissolve heat through dilation of blood vessels and are at an increased risk for tissue injury.

Skin and tissue integrity (open wounds, broken skin, scar formation, edema): Subcutaneous tissues are more sensitive to temperature variations than are superficial tissues (e.g., cold can decrease blood flow to an open wound, thereby inhibiting healing). Skin and tissue integrity (open wounds, broken skin, scar formation, edema): Subcutaneous tissues are more sensitive to temperature variations than are superficial tissues (e.g., cold can decrease blood flow to an open wound, thereby inhibiting healing).

Heat and cold can be applied in dry and moist forms (Figure 35-15). The type of wound or injury, location, and presence of drainage or inflammation are considered when selecting moist or dry applications.

Copyright 2008 by Pearson Education, Inc. Methods for Applying Dry and Moist Heat Dry heat –Hot water bottle –Aquathermia pad –Disposable heat pack –Electric pad Moist heat –Compress –Hot pack –Soak –Sitz bath

Copyright 2008 by Pearson Education, Inc. Methods for Applying Dry and Moist Heat

Copyright 2008 by Pearson Education, Inc. Methods for Applying Dry and Moist Cold Dry cold –Cold pack –Ice bag –Ice glove –Ice collar Moist cold –Compress –Cooling sponge bath