My FIL who is 81 has had a sore shoulder and put some deep heat treatment on (he has used deep heat many times on his leg with no problems) but this time has had a severe reaction.He used it about 4 days ago and his skin looks burnt a solid dark red/purpley colour very blistered and kind of a bit leathery.It is clearly causing him agony but he won't see a doctor or even pharmacist.The area is about the size of a dinnerplate.I feel it should at the very least be dressed to prevent infection.has anyone got any ideas how to treat this ?