I'm not sure how to ask the question, Doc. If you look at the study is says as I understand it, as you acclimitze to heat, you have reduced cardiovascular strain. In other words, you are exposed to heat, your system speeds up. As you acclimatize, you system doesn't need to speed up as much. The question is does this benefit you all around - reduces your cardiovascular strain 24/7? Or is there only a measurable reduction in strain during the time you are exposed to heat stress?
I guess to put it practically, do you do more for your heart if you train in the heat.
I doubt it. I just think that as you continue to train in the heat, the head doesn't bother you as much.