I typically tell my patients to put a cup of uncooked rice into a sock.
Tie off the end of the sock & place in the microwave on high for 1 minute. Rice is a terrific insulator of heat. Apply the sock to the boil for 5 seconds and pull away once it gets too hot. Repeat the process for a total of 20 minutes. Perform 3-4x/day until it resolves. If it continues to worsen, go to the er.