My Husband Has In The Last Day Or So Developed

My husband has in the last day or so developed a bad rash & redness near his groin area as well as his private parts. He is 69 1/2 & suppose to have an ablation done on Friday. He has been on a NutriSystem died the last week & we were wondering if it could be related. Also, he has been drinking a lot of V8 juice (low sodium), of which the diet suggested. It is like a bad heat rash. He took a luke warm oatmeal bath, then put some Hydrocortisone cream. We were wondering if there is anything else we can do before Friday. We didn't want to have to cancel the procedure as it is suppose to help his afib condition.