In reply to Fredt:
> But this is my point. For me, they don't make me feel any warmer.
We can determine what temperature change a drink can give us.
Let's assume a 70kg body, at 36.8C.
Let's assume we drink 250ml at 70C
The resulting average temperature will be:
(70*36.8 + 0.25*70) / (70+0.25) = 36.92C
A change of +0.12C
Now let's do the same with cold (0C) water:
70*36.8/70.25 = 36.67C
A change of -0.13C
So the two drinks will give a body temperature difference of 0.25C
I'm not too sure how significant this is, but, given how carefully the body tries to regulate its temperature (within a pretty narrow range), I think it might be noticeable.
I started this analysis thinking that the difference would be negligible, but, having done it, I think there may indeed be a noticeable difference, so it's not just psychological.
I've also assumed that the entire body is warmed, but, in reality, it will only be the core, and it will take some time for that warmth to spread from the throat and stomach to the rest of the body. Thus, you will notice the warmth in your stomach and abdomen quite quickly.
And then there's almost sane's good point about not wanting the drink to freeze...