There was a question regarding whether to use heat or cold when we have an acute trauma like ankle sprain or back sprain. The well-known rule is "RICE" - Rest, Ice, Compress, Elevate. I can't agree more with resting, compressing, and elevating to stop internal bleeding and promote better blood flow. Ice can probably make you feel less painful because it's numbed, but over time blood vessels are constricted and and circulation is decreased and can cause stiffer muscles from scar tissue aka old injuries. We're told to use ice in the first 48 hours but every individual is different, who and how did we come up with this number? In fact, heat has the ability to transform and let tissue heal the right way. Heat can dilate and bring blood into the injured area and also out of it so pressure is not building up to cause swelling. If heat makes you feel better, your tissue is probably ready for heat, and you don't have to follow the first-48-hours rule.
Click on the link below to read an article by Athletic Medicine on this topic:
RICE The End of An Ice Age