My Husband Is 43 Years Old Good Health, He Suddenly

My husband is 43 years old good health, he suddenly had an allergic reaction of some sort that turned into a massive spread of a rash that caused him to swell including his face and skin turned red with heat, he jumped into the shower with cold water and his hands started to tingle and he had a minor blurry vision. His feet however did not react and are very cold. Is this severe enough to go to the ER?