No kidding. Must mean 4-6 minutes.

I figured that was air, like "cryo". Later:

similar effects for immersion in cold water for several minutes as well

40F outdoors with clothes.

Ice baths are several minutes.

The faster the thermotransfer, the shorter the cold shock period, obviously...

and even a mild case of death can kill you...be careful out there!

Activity makes a big difference. Sitting outdoors for 4-6 hours without a coat in 40F would mean hypothermia for most people. Heck, I lose peripheral circulation and get sick more easily after sitting outdoors for just an hour or two in 50F WITH a coat if it's not an adequate one.

Generally, quite a lot, as long as you stay dry. I spent 8 straight hours outside shooting pictures while standing - and occasionally lying down - on a frozen lake in northern Canada in January. It was -25C / -13F. I was perfectly comfortable, although I did have to repeatedly switch batteries with ones that I'd been keeping inside my coat.

Goal was to get pictures like this: https://goo.gl/images/imXCMy

(Those are methane bubbles frozen in the ice.)

Clothes are the reason people don't regularly die when they go skiing, or for that matter, live outside the tropics.

It's occasionally getting to -20-25 C during winters where I live, but people go around in their daily routines (only exception is children that do not have to go to school if it's below -20 C). I'm pretty sure if not the clothes, there would be a hell lots of frozen bodies around every winter.