I cook with more peppers when I feel indicators of a possible cold or flu. It seems to help. I have also read claims of it eroding arterial plaque and lowering cholesterol. Only non-suspect study a quick Goog turned up was a NIH study on lowering cholesterol on rabbits(it did!).

Anecdotally, it definitely helps to speed things along to recovery. I also find spicy food ironically helps in very hot, dry weather.

It also makes the deserts' relative cold months more tolerable. Probably not a good idea in northerly parts where sweating on a sub-0 day/night might be a hazard.

I didn't even consider that, thanks for a new perspective. Good point about sweating in freezing weather though, you're right, you definitely want to stay as dry as possible in (for example) the boreal forests of Canada.