Hello, For About 4 Years Now Whenever I Get Hot,

Hello, for about 4 years now whenever I get hot, nervous, go outside in the heat for a few seconds, exercise, basically anything that cause my body temperature to rise makes me extremely itchy all over. My head, back, torso, legs everywhere but different spots each time. The only way to temporarily cure it is to cool off with super cold water or ice, or sitting under the AC. During the reaction I can feel something like bumps on my back and chest with white tips but leave after a few minutes. It’s very depressing I can’t do anything or enjoy life without it getting in the way. Sadly we don’t have a dermatologist in the area. I also went to the doctor once but he only suggested I use a better soap....... any cure? Permanently cure? Pills? Anything?