Yep, it is the acclimating that is important.  And that always included my telling the members, adult and kids, that the swim check was NOT a race, and they could wait a day if need.  We went from sea level, literally, to a mile hight or more most years.  Between the hot, dry atmosphere and unheated pool, or other water, it could zap you.  As I got older, I always did my check the following day, both because of the change, but also my trying to keep up with the routines.    

As a retired Occupational Safety and Health professional, I think the biggest factor is not global warming, but the lack of acclimatization of people, especially the youth.  People who routinely work and play outdoors develop a physiological tolerance to heat, and not much of that happens anymore.  Most of us arrive at Camp having just emerged from cool environments of home, office, cars, etc.  Back in the 1900s when my kids were young scouts, we had a house rule that the AC didn't get turned on in the house, until we returned from Summer Camp.  Up until camp, usually the week after 4th of July, we had the windows open and worked and played outside as much as possible to get "acclimated" to the heat. I worked in a shipyard, so had to be out on the ships and shops, not soaking up the AC in the office. I remember one week when the temp topped 100 every day and the low at night was around 90, with 80-90% humidity...in coastal Virginia.  We survived by maximizing pool time and eating lightly and hydrating.  No AC in the dining hall, only in the trading post and Admin building.  Good times.

"Again, the best way to prepare for heat-related illnesses is to prevent the illness." I remember back in the day, wearing a cold-water soaked, full-size necker.* I do worry that global warming with more frequent, severe storms and heat waves will cause the extinction of summer camp. https://www.scouting.org/health-and-safety/safety-moments/heat-related-illness/ *Note: Though hard to find on the trail, wrist dipping in a cooler with ice water mix also offers relief too.

It's a nice article.  Hopefully, it's an uplifting story.

... and this outstanding piece published last Friday in The Dispatch "Scouting Hasn't Lost Itself" (subtitled "Girls now have more opportunities for Scouting’s formative experiences."): https://thedispatch.com/article/scouting-hasnt-lost-itself/