For Acute or new injuries that are less than 7 days old you should ice for 20 minutes every day for 7-10 days to break the inflammation cycle. A good ice pack brand is Elastogel which allows you to strap on a flexible icepack and provides good cold therapy.
For older injuries and chronic muscle problems, you should use heat to relax the muscles to help the pain. It should improve your symptoms and if for any reason it makes them worse, then stop.
Will it get better?
Most sprains and strains will improve on their own within about 2 weeks. If your pain and problem is not 90% better after 2 weeks, it will probably not improve on its own and it is best to have it checked. Getting the right information on how to care for the injury will go a long way toward keeping it from turning into a long-term problem.
Should I brace it?
Maybe. There are many different braces and types of options out there, and more expensive does not always mean better. You are best to check with a physical therapist to make sure you know what you should use and how to use it. A poorly fitting brace can be as bad as no brace, or be a waste of money.
Some body parts do better in a brace than others. For example, ankles do well in braces, backs rarely do.
When should I call for a physical therapy appointment?