Hot And Cold Therapies Explained
Margit Nezold, Student Physiotherapist and AQ Volunteer
What are the different types of cold therapy?
- Ice packs – commercially available, can be lower than 0 degrees coming out of the freezer
- Ice baths – body part is immersed in 16-18 degree cold water
- Vaporizing sprays – very short lived effect (less than 30 seconds)
- Ice massage – frozen Styrofoam cups filled with water used for massaging (after the bottom of the cup is peeled off), especially good for small areas like ankle sprains
What are the different types of heat therapy?
- Wax bath – immersion of body parts in hot paraffin wax, often used for hands
- Heat packs - 40-42 degrees (can cause burns if hotter than that)
- Hydrotherapy – exercise in water heated to 36-41 degrees
- Infrared radiation – dry heat, has similar effect to other types of heat therapy
Cold or heat?
It depends on the patient’s preference – some people prefer heat, and some prefer cold.
Cold therapy is usually recommended for acute stages of inflammation like a recent sprain. Heat can increase oedema (swelling) and make inflammation worse; therefore, it is not always recommended for acute injuries.
Many people with chronic conditions find heat based therapies very relaxing. Applying heat promotes blood flow and muscle relaxation in sore joints. Heat can also help improve the flexibility and range of movement in the ligaments and muscles which surround your joints, making it a little easier to move around and complete daily tasks.
Both hot and cold therapy can reduce pain and muscle spasm (painful muscle contractions). However, cold therapy only reaches very superficial tissue, and is therefore less useful for joints that lie deep (like the hip joint).
Are there any risks or detrimental effects when using heat or ice?
Yes, there are.
Both heat and ice can cause burns – if the heat pack is too hot, for example, or an ice pack is left on the skin for too long. As a precaution, heat and ice packs should be wrapped in a towel before placing it onto the affected body part, and the skin underneath should be frequently checked. As a general rule, ice packs are used for 20 minutes, and then removed for 1-2 hours, before replaced.
People with certain diseases should not use ice therapy:
- Raynaud’s disease (a disease that causes the blood vessels in hands to contract)
- Cryoglobinaemia (can occur in people suffering from Rheumatoid Arthritis or systemic lupus erythematosus: abnormal blood proteins can precipitate at low temperature and block blood vessels)
Heat and ice should not be used if your skin sensation is impaired (if you are unable to feel heat or cold), because there is a high risk that you could suffer burns. This often happens in people suffering from diabetes. As a precaution, a hot/cold skin test is performed before applying heat or ice: two test tubes are filled with hot and cold water, and alternatively placed on the skin; if you can’t feel the difference, you should not use heat or ice.
Cold therapy can cause hypertension (high blood pressure), while heat can cause blood pressure to drop, especially if large areas are treated. If you suffer from hypertension (high blood pressure) or hypotension (low blood pressure), you should be careful with cold or heat therapy.
Heat or cold therapy should not be used over open wounds, damaged skin, or if you suffer from skin conditions like dermatitis or rash. Heat should also be avoided over areas that have recently bled (like bruises).
Information provided on this website is of an educational nature and should not be relied on as medical advice. You should consult with your health care professional about the appropriateness of this information for your particular case.