There is always a lot of debate as to what is the best for the treatments of injuries. Do you put on a heat pack or is it better to ice? It is funny that there could be so much debate for a fundamental of injury management.
The principal revolves around blood flow and inflammation. If you apply heat to the area you will cause the blood vessels to widen which brings nutrients to the injured area. If you apply ice to the area you will cause the blood vessels to narrow and reduce bleeding and inflammation.
As soon as you sprain a joint like an ankle or suffer a corky you should always apply ice to help narrow the blood vessels and slow the bleeding and rate of inflammation. This should be applied for 2-3 days dependant on the severity of the injury. After this the ruptured blood vessels close and the inflammation stops progressing. It is at this stage that heat is best as you now want to bring good nutrients with more blood flow to the area.
Where it gets tricky is what do you do when you injure an area that is too deep for ice or heat to penetrate. An example would be a back injury. If you have injured a joint in your back then the ice will not penetrate deep enough through the muscles to affect the injury. It will numb the pain but it won’t reduce inflammation. The best in this instance is to apply heat. Heat will relax the surrounding musculature and will also have a natural pain killing effect.
It is better still to try to avoid the injuries all together to avoid the heat vs ice argument!