The therapeutic use of cold or warmth is a well-known physiotherapeutic treatment. Whether to use heat or cold on the affected area depends on the type of pain. Heat has been known for generations to be an effective way to relieve pain caused by muscle strain and tension, and in many cases applying external heat sources can relieve muscle pain. Cold is recommended for acute conditions, such as acute inflammation or injuries, e.g. sports injuries such as sprains, contusions, bruising, and swelling. If you are in doubt as to whether to apply heat or cold, please consult your pharmacist or physician.