The adaption for more sweating was mentioned during the women’s marathon run in Tokyo. I’m not sure that would be evolution in a particular region of the world, or evolution in general for human beings. It is an adaption most humans are capable of.
Human beings have the ability to adapt to environment, sweating more efficiently when spending a lot of time in hot climates or doing regular intense exercise is a really phenomenon. Also, building specific types of fat in colder climates and changes in blood and arteries.
People overuse this idea of acclimation as an excuse for how they feel in the heat or cold. I hear it all the time living in Florida. They will say their blood has thinned living here and now 60 degrees feels cold. The truth is, just being here a day people will complain 60 degrees is cold, and that is not an adaption, that is thinking you only need shorts and a t-shirt in Florida 365 days a year and refusing to put on warmer clothing. Plus, we have higher humidity which makes cool weather feel colder.
Cold weather can thicken the blood though as an attempt to keep you warm. Thickens and arteries and veins move in closer to the interior of your body away from the skin. Blood concentrates towards vital organs and your extremities are at risk. Within time your body adjusts so these protections are not so severe. Sudden cold weather is dangerous. I know the last thing I need is thicker blood and increased risk of clotting.
In the US we don’t acclimate much, because we have central air conditioning and heat in most places where the weather is more extreme.
If evolution has been affecting our ability to handle various climates, the advent of air conditioning and heaters certainly has put a dent in the possible continuing process into the future.
I’m no expert, but this is what I’ve learned over time.