Wasnt there a study or paper claiming injury rates go up with temperature? So training this way may be harmful
dno, don't remember that.
training light in the heat doesn't sound to risky to me. using the heat to make the effort harder, while actually going at lower intensities, seems safe for the body. definitely seems less safe when it comes to the heart, could get very stressful. but using good judgement is important. lots of dangerous symptoms will manifest themselves early (sensitivity to bright light/sunlight, feeling cold, etc).
pc!