last time i raced in the summer i almost passed out comming down the return road ,that was on my 3rd run. then had to sit in my truck with the ac on and was really sick(sucks gettin old) but since then ive been workin out a little to biuld my cardio,i might give it another shot once or twice this summer, i really dont mind the heat long as it dont drain me,but if it bothers me im over summer runnin.