Everything mentioned above is sound. With four children actively in sports and constant injuries, I've heard and been advised of everything. In the end, it still is confusing to me. As l.c.o., states swelling and inflammation is your body's way of healing itself. So icing can halt healing but it also reduces inflammation and helps with pain control. Heat promotes blood flow to the injured area which promotes healing but heat is also not been known to be recommended when swelling is involved because swelling is caused by bleeding in the tissue and heat just draws more blood to the area. RICE is always a standard by doctors. We've also done therapeutic contrasting therapy (ice, heat and then ice again) which can allegedly speed recovery. Generally, every doctor we've seen advises ice as a treatment modality immediately after an injury for its ability to reduce inflammation and swelling in the injured area and for its pain relieving properties. Superficial heat therapy is commonly used in physical therapy practices in the non-acute injury phase (after first 72 hours of injury) as a pain relieving and muscle relaxing treatment modality and is also usually recommended for chronic injuries. Superficial heat can also be effective in pain relief because it increases blood flow which warms the underlying muscles. I've deduced that ice for acute injuries, the first 48 hours and then heat may be applied after 72 hours. The only common denominator I've found is rest and elevation.