[Low-Tech] [High-Tech] Portable cooling: higher-TL replacement of water jugs?

[Flyndaran]

Originally Posted by Bruno

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My sister got honest-to-god heat stroke and they wouldn't let her out until she arranged to go stay with a friend with A/C and promised to buy a window A/C unit and basically hug it for the rest of the summer.

I know that while the (incredibly awesome don't take it from me or I will throat punch you) AC unit I got during a major heat wave made me feel better while in front of it, it reversed my slowly burgeoning heat tolerance. It made so much as going more than two feet away so much harder and stressful than it had been before.