We were also told that to treat heatstroke tossing someone in the lake and then treating for shock was somewhat preferable…
There are quarries around where I am that have signs posted to not swim there in the Spring. Yet, like clockwork, 1-2 people drown each Spring.
Every single year, during the first "hot" day of late Spring/early Summer, kids will get on their bikes, go to the local quarry where they've swum a million times before, and die from exposure.
The quarries are deep and surrounded by trees. Most of them don't receive any direct sunlight. So, while the ambient temperature may be 75F, the quarry water will still be near freezing. A kid will jump from up high on the quarry ledge down into the water, go into shock, and die before they can swim to edge.
Again, this happens every single year.