List the function of acclimatization?

Can a person have the same VO2Max in a completely different activity?

Daniel, the swimmer with the fastest time on the college swim team, routinely hyperventilates before a meet, as he says "to sock some more oxygen into my lungs so I can swim longer without having to breathe." "Furthermore, my heart won't have to adjust it's output". Which organ(s) would actually require more oxygen that Daniel may not be realizing? Why so?

Why are sweating and panting the cooling adaptation of last resort?

When a person is in a state of heat exhaustion, trying to reduce body temperature is a priority over trying to maintain MAP. With this in mind, explain why people in a state of heat exhaustion have a rapid heart rate, but low stroke volume.