What can you do about cat that gets heat rash or skin irritations?

Tweet

Here in the South, it's perpetually hot, until late December. And, for that reason, our cats suffer from heat rash on occasion. Most times it's not so bad. But, last year, my big female cat EB, picked all the hair off one spot near her stub tail. She just kept cleaning herself in that spot, until the hair came off. I think it was heat rash or some type of irritation. I tried to apply ointment, but was afraid that she would lick off the stuff and get sick. What can be done about a cat that gets heat rash or dry patches? Are there any types of over the counter medications or creams that have worked for your cats, when they get irritated skin? Would appreciate suggestions.