ice for 10 minutes, off for 15-20 minutes, repeat. You could also alternate ice/heat for 10/10. For heat, you can take a towel right out of a super hot dryer. Fold it a couple times to keep it hot longer - even better if it's just a bit damp still. Or you can use a heating pad on low. Not really necessary to do the heat, but it would feel good. 
