Heat Application
Heat applied directly to the patient’s body raises tissue temperature and enhances the inflammatory process by causing vasodilation and increasing local circulation, which promotes leukocytosis, suppuration, drainage, and healing. Heat also increases tissue metabolism, reduces pain caused by muscle spasm, and decreases congestion in deep visceral organs.
Direct heat may be dry or moist. Dry heat can be delivered at a higher temperature and for a longer time than moist heat. Devices for applying dry heat include the hot-water bottle, electric heating pad, K pad, and chemical hot pack.
Moist heat softens crusts and exudates, penetrates deeper than dry heat, is less drying to the skin, produces less perspiration, and is usually more comfortable for the patient. Devices for applying moist heat include warm compresses for small body areas and warm packs for large areas.
Direct heat treatment can’t be used on a patient at risk for hemorrhage. It’s also contraindicated if the patient has a sprained limb in the acute stage (because vasodilation would increase pain and swelling) or if he has a condition associated with acute inflammation such as appendicitis. Direct heat should be applied cautiously to pediatric and elderly patients as well as to patients with impaired renal, cardiac, or respiratory function; arteriosclerosis or atherosclerosis; or impaired sensation. It should be applied with extreme caution to heat-sensitive areas, such as scar tissue and stomas.
Equipment
For All Methods
Patient thermometer ▪ towel ▪ adhesive tape or roller gauze ▪ absorbent, protective cloth covering ▪ Optional: sterile gloves.
For A Hot-Water Bottle
Hot tap water ▪ pitcher ▪ bath (utility) thermometer.
For A K Pad
Distilled water ▪ temperature-adjustment key.
For A Warm Compress or Pack (Sterile or Nonsterile)
Basin of hot tap water or container of sterile water, normal saline, or other solution, as ordered ▪ hot-water bottle, K pad, or chemical
hot pack ▪ linen-saver pad ▪ bath (utility) thermometer ▪ Optional: forceps.
hot pack ▪ linen-saver pad ▪ bath (utility) thermometer ▪ Optional: forceps.
Sterile or nonsterile items, as appropriate, include compress material (flannel or 4″ × 4″ gauze pads) or pack material (absorbent towels or large absorbent pads), cotton-tipped applicators, forceps, a bowl or basin, a bath (utility) thermometer, waterproof covering, a towel, and dressings.
Preparation of Equipment
Hot-Water Bottle
Fill the bottle with hot tap water to detect leaks and warm the bottle; then empty it. Run hot tap water into a pitcher and measure the water temperature with the bath thermometer. Adjust the temperature as ordered, usually to 115° to 125°F (46.1° to 51.7°C) for adults.
Pediatric Alert
Adjust water temperature to between 105° and 115°F (40.6° to 46.1°C) for children younger than age 2.
Elder Alert
Adjust water temperature to between 105° and 115°F for elderly patients.
Next, pour hot water into the bottle, filling it one-half to two-thirds full. Partially filling the bottle keeps it lightweight and flexible to mold to the treatment area. Squeeze the bottle until the water reaches the neck to expel any air that would make the bottle inflexible and reduce heat conduction. Fasten the top and cover the bag with an absorbent cloth. Secure the cover with tape or roller gauze.
Electric Heating Pad
Check the cord for frayed or damaged insulation. Then plug in the pad and adjust the control switch to the desired setting. Wrap the pad in a protective cloth covering, and secure the cover with tape or roller gauze.
K Pad
Check the cord for frayed or damaged insulation, and fill the control unit two-thirds full with distilled water according to the manufacturer’s directions. Don’t use tap water because it leaves mineral deposits in the unit. Check for leaks, and then tilt the unit in several directions to clear the pad’s tubing of air. Tighten the cap, and then loosen it a quarter turn to allow heat expansion within the unit. After making sure the hoses between the control unit and the pad are free of tangles, place the unit on the bedside table, slightly above the patient so that gravity can assist water flow. If the central supply department hasn’t preset the temperature, use the temperature-adjustment key provided to set the temperature on the control unit (the usual temperature is 105°F [40.6°C]). Then place the pad in a protective cloth covering and secure the cover with tape or roller gauze. Plug in the unit, turn it on, and allow the pad to warm for 2 minutes.
Chemical Hot Pack
Select a pack of the correct size. Then follow the manufacturer’s directions (strike, squeeze, or knead) to activate the heat-producing chemicals. Place the pack in a protective cloth covering and secure the cover with tape or roller gauze.
Sterile Warm Compress or Pack
Warm the container of sterile water or solution by setting it in a sink or basin of hot water. Measure its temperature with a sterile bath thermometer. If a sterile thermometer is unavailable, pour some heated sterile solution into a clean container, check the temperature with a regular bath thermometer, and then discard the tested solution. Adjust the temperature by adding hot or cold water to the sink or basin until the solution reaches 131°F (55°C) for adults. Adjust the water to 105°F (40.6°C) for an eye compress.
Pediatric Alert
Adjust the water temperature to 105°F (40.6°C) for children.
Elder Alert
Adjust the water temperature to 105°F for elderly patients.
Pour the heated solution into a sterile bowl or basin. Then, using sterile technique, soak the compress or pack in the heated solution. If necessary, prepare a hot-water bottle, K pad, or chemical hot pack to keep the compress or pack warm.
Nonsterile Warm Compress or Pack
Fill a bowl or basin with hot tap water or other solution, and measure the temperature of the fluid with a bath thermometer. Adjust the temperature as ordered, typically to 131°F (55°C) for adults or 105°F (40.6°C) for an eye compress.
Pediatric Alert
Adjust the water temperature to 105°F (40.6°C) for children.
