Are you on any medications that suggest that you avoid sunlight? Also, are you on any medications containing steroids?

I know of several meds that you can take that can cause severe sunburn, flu-like symptoms and my mom said steroids suppress the immune system.

Sometimes I feel that way, but normally when it's really hot or really cold and I'm used to breathing the 'recycled air' from the heating or AC unit and going outside into that air always makes me feel sick.