Your best bet is a trip to the vet. Silver Sulfadiazine will work much better than OTC antibiotic cream, especially for a burn, but you will need a RX. And get a thermostat ASAP. No UTH is safe without one, no matter what the packaging may say. Here's a link to one thats pretty affordable:
http://firestormreptiles.com/weblog/...hermostat.html