Szechuan spicy food.-2
Perhaps it has less to do with feeling cold, and more to do with what vegetation grows better in the region? Certainly chilli peppers are produced en-masse in China and actually account for about half of the global production.
If we break it down even further, we'll realise that Szechuan province contributes a large percentage of the production of China overall and would suggest that food biases there are more to do with what is easily and most profitably produced.
~ Helga