I read that article you linked to. And I'm pretty sure that their claims about ingesting cold vs hot fluid to combat hypothermia are going to be debate for a VERY long time, by the majority of people who live were there IS snow. I'm in the same area as the conference they referenced and having lived here most of my life and liking winter, I think they are lacking on that count.

Hot fluids are passive calories. If you doubt that, here is a simple experiment. Take a cold shower. Take your oral temperature. Quickly drink a liter of hot water(chug it if you can). Take your temperature, and again in ten minutes. If taken orally, you'll get a spike for obvious reasons immediately afterwards, but your temperature will climb a few degrees.

It isn't long term, it's a short term effect. And it's probably mostly morale, aka mindset, that is effected. You FEEL warmer, and unlike alcohol, it isn't a trick. I'll stick with warm fluids in winter and cool in summer, thank you.