I am not a doctor and I have rarely stayed at a Holiday Inn Express so take these statements with a grain of salt.

My buddy's girlfriend came home from a winter trip to the BVI with something that looked just like that on her forearms and shoulders. It was more bumpy than simple burn. She was freaking that it may be some parasite or horrible bacteria thing. Doc back home told her it was a polymorphous light eruption. Some type of an overreaction to a sunburn. She is a fair skinned redhead who turns pink in about 15 minutes at the pool.

I hope your wife can get some relief.