Throughout the film from when the temperature starts to drop in all locations around the world you can never see any ones breath! You can see your own breath as a steamy cloud even when the temperature is only about 12 degrees celsius.

It is particularly stupid looking when Jakes character leaves the library with the other two guys to go to the ship and the "big freeze" is about to occur and you still can't see their breath! Nor when his Dad and his colleagues are trekking through the snow. It would have so much more impact if these scenes were made more realistic, by seeing their breath!