Ice is most commonly used for acute injuries. If you have had a recent injury with swelling, you should be using ice. Ice packs can help minimize swelling around the injury along with reducing muscle spasm and pain.
Ice packs are often used after injuries like sprains have occurred. Applying an ice pack early and often for the first 48 hours can help minimize swelling, and decreasing swelling around an injury will help to control the pain.
Never place ice directly on an injury; keep the pack moving to avoid ice burns. Never treat with ice for more than 30 minutes, and remove the pack immediately if the injury appears bright pink or red.
Heat treatments should be used for chronic conditions to help relax and loosen tight muscles. Never use heat where swelling is involved because swelling is caused by bleeding in the tissue, and heat just draws more blood to the area.
Heating tissues can be accomplished using a heating pad, or even a hot, wet towel. When using heat treatments, be very careful to use a moderate heat for a limited time to avoid burns. Never leave heating pads or towels on for extended periods of time or while sleeping.