Could Chills And Rashes On Thighs Be Due To Acetaminophen?

My husband is currently on medications for his heart condition, Angina. His doctor prescribed 1. Metoprolol tartrate 25 mg 1 tablet 2x per day (for blood pressure beta blocker; used to treat angina ) 2. Simvastatin 20 mg 1 tab every evening (cholesteral) 3. Ranexa 500 mg tabs . 2 tabs 2x per day (bata blocker for cronic angina 4. 81 mg tab aspirin 1 per day. 2 days ago after working for a while in the yard, his back began to bother other him. He iced it for a couple of days (off and on). For 2 days he has also been taking Equate Arthritis Pain medication for the pain. It contains Acetaminophen. Now he is experiencing chills, very cold hands, shaking of his hands and a rash on his thighs and some on his but. He is resting in bed now and has a Doctors appointment in the morning . Should I be concerned during the night? Could the Acetaminophen be reacting with his other medications? Could this reaction be from the Arthritis pain medication he took? Thanks for any assistance you may provide. Worried Wife YYYY@YYYY