Recently I was working outside in roughly 100 degree weather (although in the shade) for about 11 hours or so. Earlier today I noticed that there were some small, relatively unnoticeable bumps mainly on my cheeks, forehead, and under my eyes. I decided to wash my face a bit with a wash cloth and it made them a bit more red and noticeable (which is why they are so obvious in the picture). Although I'm almost positive it is nothing more than a cosmetic issue I'd like to nip this in the bud as soon as possible and, unfortunately, because I will be doing these long days outside about every other week I'd also like to see what I could do to prevent this from coming back.
Additional notes: I'm 21 now and I've never had any kind of skin problems other than the occasional pimple even throughout my adolescent years, so this is definitely new for me. The redness that isn't part of the bumpiness is not related, the picture just came out a little weird with that. Any help is appreciated.