I used aloe vera leaf from my backyard and didn't get burned at all. Make sure you clean it well. I washed the leaf with diluted dish washing soapto remove dirt, dried it, then used rubbing alcohol to disinfect. I used clean knife to remove the original cut and the thorns, stored in refrigerator. Make sure you use it right after each session and continue to another week or two after the radiation therapy is done. Don't use it over the blisters. Wish you all the best. Hugs.