It depends. There's a lot of mixed literature out there between hot and/or cold therapy. Ultimately, it will depend on the type of injury you are dealing with as well as what stage of healing you are in. Generally, if you are dealing with acute pain and notice that there is inflammation, ice would be your best bet. If you are dealing with chronic pain and stiffness, heat would be most likely be recommended. However, consult with your physiotherapist and they will be able to help determine what would be the most beneficial for you.