Red Spots On Body, Itchy. Reason?

Ok I see red spots that are itchy,patchy,and red in all different sizes one my face and body. It started yesterday with a few and I thought they were just bug bites, then I go outside and it starts a little more but very noticeable . Then I go to the rodeo for about 2 hours and I go home take another shower and see in the mirror everywhere on me! Its all over me on my face , neck , around my ears, my legs and thighs , my arms, stomach and back kneed help. I think because I got cold from showering two times and going out when it was chilly out but I don t know HELP!