When do I use Heat and when do I use Cold?

By Adelaide Women's Physio | May 16, 2017

This is a question frequently asked by our clients in both consultations and exercise classes at Physiotherapy for Women. Hot and cold therapies have been used for centuries as healing modalities to promote health and well-being. Our physiotherapists will help you in your choice of thermal energy (hot or cold) with the following answers.

Cold Therapy Applications

  • When is an ice pack best used?

During the early acute phase of injury (first 24 to 48 hours) cold therapy or cryotherapy is a common choice. At this time of tissue trauma, cold can be applied in the form of ice packs, cold towels, ice compresses and iced water baths. Inflammation, swelling and muscle spasm are features of acute trauma.

  • What effect does cold have on tissue?

Cold therapy assists in reducing swelling by narrowing the blood vessels and decreasing blood flow to the injured tissues. As skin temperature is reduced, large diameter nerve fibres are stimulated. This leads to a local analgesia or numbing of tissues, which helps in pain control.

  • How long is an ice pack applied for best effect?

Apply the ice pack or cold compress to injured tissue for 15 to 30 minutes maximum. Do not apply again for a minimum of 2 hours. Usually 3 to 4 applications of cold in a 24 hour period are advised.

  • What are the safety issues with cold therapy?

Avoiding “ice-burns” to skin is essential. It is always necessary to place a damp cloth between the skin and the ice pack. Never place a cold pack directly on the skin.

Do not use cold therapy in the following situations: open or infected wounds; cardiac issues; skin numbness; poor circulation; Raynaud’s disease; dermatitis or eczema flare-up; hypersensitivity to cold temperatures.

 

Heat Therapy Applications

  • When is a hot pack used?

The application of heat can be beneficial when the acute phase of injury (after 48 hours) is over, or when chronic soft tissue and joint pain and tightness are being treated. Heat can also be used before stretching, physical activity, soft tissue treatment or massage.

Heat can be applied in the form of heated gel, grain or heat-bead packs, electric blankets and pads, a warm bath, spa or sauna.

  • What effect does heat have on tissue?

Heat therapy assists in promoting healing, reducing long standing inflammation, decreasing muscle spasm and pain, enhancing blood flow, muscle flexibility and joint motion.

Heat increases blood flow to tissues by dilating blood vessels. This assists in delivering oxygen and nutrients to the tissue cells, removing cell waste products and promoting tissue healing.

Relaxation of muscles and the nervous system is enhanced in most people when warmth or heat is applied.

  • What are the safety issues with heat therapy?

Always protect skin from heat burns by placing several layers of towelling between the skin and hot pack.

Never lie down or fall asleep on a hot pack as both situations increase the chance of skin burn.

Application of a hot pack should be for 15 to 20 minutes.

Discontinue heat treatment if there is an increase in discomfort.

Maintain hydration by drinking water before and after immersion in baths, spas or saunas.

Pregnant women need to avoid immersion in hot baths, spas and saunas.

Very young and people who are elderly or frail need to be monitored for the entire time of heat therapy. Avoid warm water and saunas with these age groups.

Avoid heating in the following situations: acute injury or tissue trauma; open or infected wounds; swelling; severe bruising; areas of skin numbness; peripheral vascular disease; diabetes; poor circulation; poor thermal regulation; abnormal tissue and tumours.