Local Application of heat and cold to the body can be

therapeutic, but before using these therapies, the nurse must

understand normal body responses to application of heat and cold and

how and when to use.

Heat-loss via sweating and vasodilation

Heat conservation via vasoconstriction, curl-up

Heat production via shivering, movement

What happens if heat is applied to a large body

area?

Diverts large supplies of blood from the internal organs

Drop in the Blood Pressure

Which could lead to a safety issue

Occurs through stimulation of temperature-sensitive sensory nerve endings/ thermal receptors in the skin.

Sent up the spinal cord to the hypothalamus in the brain where impulses are recognized as hot or cold

Protective adaptive responses are triggered: cold= vasoconstriction; hot= vasodilation

Heat Vasodilation Increase capillary

permeability Increase local cellular

metabolism Increase blood flow to

an area Increase lymph flow Increase muscle tone

Cold Vasoconstriction Decrease capillary

permeability Decreased local cellular

metabolism Decreased nerve

conduction Decreased blood flow

to an area Decreased lymph flow Decreased muscle tone

Nerve receptors strongly stimulated initially

Declines rapidly during first few seconds

Declines slowly over the next half hour

Receptors adapt to the new temperature

Exceeding normal temperature ranges can damage tissues

Occurs at the time that maximum therapeutic effect of hot or cold application is achieved

Heat produces maximum vasodilation in 20-30 minutes.

Continuation beyond 30-45 minutes causes tissue congestion, the blood vessels constrict

Now the opposite effect is occurring because of reflex vascular constricton.

Recovery time of one hour is advised before reapplication

Maximum vasoconstriction occurs when the skin temperature reaches 150 or in about 30 minutes to one hour.

Vasodilation begins as a protective device to prevent the body tissue from freezing

Recovery time of one hour is best before reapplication.

The nurse should assess WHY thermal therapy is being utilized

Relax muscles

Reduces swelling

Accelerates the inflammatory process to fight infection

Promotes healing and formation of new tissue through accelerated cellular metabolism

Reduction of pain

Duration and degree of heat or cold applied Body part Condition of the skin / body surface covered Prior skin temperature Body surface area covered by application Age– very young or elderly Physical condition

Neuro-sensory impairment

Impaired mental status

Impaired circulation

Immediately after surgery or injury

Hemorrhage

Check the order, check armband

Assess general condition of the patient

Assess the skin area where application going

Check functioning of equipment

Reassess patient and response in 15 minutes

Stop treatment at designated time

Examine the place where the treatment will occur.

Record the patient’s response

After applying a heat treatment, the patient puts on call light and says it is too hot.

What should the nurse do?

◦Aquatherma pad, K-pad, disposable instant heat pack, gel-filled heat packs, heating pad, heat lamp, thermal blanket

◦Sitz bath, compresses, whirlpool therapy, paraffin bath

◦ Ice bags, ice gloves, ice collars, chemical cold packs, hypothermia blanket

◦Cold soaks, cold packs, cooling sponge baths

Do explain to the patient sensations to be felt during the procedure

Do instruct the patient to report changes in sensation or discomfort immediately

Do provide a timer, clock, or watch so that the patient can help the nurse time the application

Do keep the call light within the patients reach

Do refer to the agency’s policy and procedure manual for safe temperatures

Do not allow the patient to adjust the temperature

Do not allow the patient to move an application

Do not place the patient in a position that prevents movement away from the temperature source

Do not leave unattended a patient who is unable to sense temperature changes or move from the temperature source

Patient says that the heating pad must be broken because it no longer feels warm.

What should the nurse do?

The patient had an edematous ankle and the nurse applied an ice pack as ordered.

Later when she assesses the ankle, it is more edematous than earlier in the day.

What should the nurse do now?