Mine‘s getting so accustomed to cold showers that I a) absolutely do not mind cold water for swimming etc. anymore and b) could not enjoy warm or hot showers anymore. They just weren’t nice at all.
I could walk both ways up a hill both ways in the snow after dialysis treatment.
Past tense because I got a kidney transplant.
Which caused a very rare Cancer (1st condition to get it, you must've never gotten Epstein Barr virus, ever, which 90-95% of the world has. Second is getting a transplanted organ that carries the virus lol).
Which led me to weird flex #2: I have unusually high cold resistance and can also mentally raise my body temperature. This was helpful when having to walk to the patient hotel in a strong blizzard with nothing but hospital clothes.
Unfortunately that means I do terribly in the heat, and there's not much AC in Finland for the summer...
The funny thing is I grew up in El Salvador, and then Texas.