The immune system of the skin is sensitive to the environment. Sunlight and air temperature normally affect the skin, but, if you have Bullous Pemphigoid (BP), which is an autoimmune disease, getting sun or too much heat can lead to blistering.

Bullous pemphigoid (BP) is a rare skin condition that causes large, fluid-filled blisters. In reviewing evidence of food-related triggers, find out which foods may trigger BP.