Splints and bandages should never be tight, as they can constrict the blood flow and cause further damage. If the blood return is sluggish, the bandage must be loosened or removed immediately. Whereas cold therapy can be applied immediately to an injury, and continued through the rehabilitation phases for as long as there is swelling, bruising and pain, heat should only be applied, if at all, in the recovery phases of rehabilitation. Applying heat draws blood to the skin under the heat source. Therefore heat is not appropriate in first-aid.
Heat is used later on to relieve muscle tension, promoting relaxation.
Creams Massage, like heat, aggravates the situation when an injury has just happened. Any cream applied must be laid gently on the skin and allowed to soak in. If you rub it in, not only do you risk increasing internal bleeding, but you could stimulate blood clotting and bone formation in torn muscle fibres.