Heat Treatments Health Article

Definition

Heat treatments are therapeutic applications of superficial or deep-heating agents to areas of the body.

Purpose

Thermal agents are used therapeutically to:

• decrease pain
• decrease muscle spasm
• decrease muscle tightness and increase flexibility
• prepare joints and muscles for exercise
• increase local blood flow to the area, thus promoting tissue healing

Precautions

Therapeutic heat treatments should not be used in individuals who have bleeding or recent hemorrhage, an acute inflammatory process, or local infection near the point of application. Furthermore, heat treatments should not be used over areas of malignancy, decreased sensation, or vascular disease. Heat treatments also should be used with caution on individuals with heart, lung, or kidney diseases. Deep heat treatments should not be used on areas above the eye, heart, or on a pregnant patient. Deep heat treatments over areas with metal surgical implants should be avoided in case of rapid temperature increase and potential for injury.

Description

There are two type of heat treatments: superficial and deep. Superficial treatments are applied to the skin over the involved area. Depth of heat depends on types of tissue and ranges from 0.19 in (0.5 cm) to 0.39–0.78 in (1–2 cm). Heat depth also depends on amount of fat in the area, as fat is an insulator. There are four different ways to convey heat:

• Conduction is the transfer of heat between two objects in direct contact with each other.
• Conversion is the transition of one form of energy to heat.
• Radiation involves the transmission and absorption of electromagnetic waves to produce a heating effect.
• Convection occurs when a liquid or gas moves past a body part creating heat.

Hot packs, water bottles, and heating pads

Hot packs are a very common form of heat treatment using conduction as a form of heat transfer. Moist heat packs are readily available in most hospitals, physical therapy centers, and athletic training rooms. Treatment temperature should not exceed 131°F (55°C). The pack is used over multiple layers of toweling to achieve a comfortable warming effect for approximately 30 minutes. More recently, several manufacturers have developed packs that may be warmed in a microwave prior to use.

Hot-water bottles are another form of superficial heat treatment. The bottles are filled half way with hot water between 115–125°F (46.1–52°C). Covered by a protective toweling, the hot-water bottle is placed on the treatment area and left until the water has cooled off.

Electrical heating pads continue to be used as a home treatment, but safety and convenience issues limit their use in healthcare settings.