Sun and heat allergies are like regular allergies and are an immune system response to a substance that is normally harmless. Having true heat and sun allergies will occur only in certain people that are sensitive. It is not clear why some people will develop allergies to the sun and heat and there is evidence that some forms are inherited.™Some people have an allergic reaction to the sunlight. The body will be able to tell when it is about to have a dangerous reaction to sunlight and it will…See More