Honestly I don't find running in the heat that bad, humidity etc sucks but it's so great for my lungs and asthma so I feel like my body weirdly thrives in this environment when I train through the seasons summer is always my best. It also takes much less energy to be hot than cold - your body burns extra energy in the cold with trying to keep the body warm whereas sweating is passive in the body so I'm going to go with that 😂🫶🏻