Hi granny sorry to hear that your son is sick. Will he get into a cool bath? If not see if he will hold ice packs under his armpits or in his groin area. Those are to two places that cool a high fever fastest. My youngest daughter would spike a fever to 105* in 5 mins if she had a illness with fever. Then she would go into convulsions. I'm thinking with his crohnes he probably isn't able to take motrin. If he is able to take it, dose him with that and if in 2 hours his temp is still over 103*, give him 2 Tylenol. This was doctor recommended, have had to do on many occassions with my daughter & granddaughter. If he won't do the ice packs, keep rinsing his T-shirt in cold water. With him being that warm the shirt will be warm in a couple minutes tops. Poor guy, hope he feels better soon!