Sickness Under The Sun. Why Does That Happen?

Hello. I have been wondering about this for a while, and have finally decided to look into it. For a few years now, when I go outside on a hot, sunny, summer day, I start to feel sick. I get severe headaches , nausea , dizziness , and fatigue . I have recently noticed that my skin gets red and blotchy. While I don t feel well in just heat, these symptoms usually only occur when the sun is out, to the extent of the symptoms starting to go away when the sun becomes covered by the clouds.