Elevation of the injured area limits swelling by draining the fluid. Once the injury is under control, you need to get back in shape. You need execute a conditioning program to restore motion and strength to the injured area. Until you do, you risk further injury. Because there is controversy about applying heat, I've looked at several sources on the web for information on when to use heat and when to use cold.
Heat promotes healing because it promotes blood flow.
It also relaxes muscles and eases pain. The disadvantage of heat is that it can increase swelling. That's why cold is recommended right after an injury. Heat is recommended for later when swelling is gone. Heat can be useful after about 48 hours.