As a Brit, I thought "are they just describing the 'stiff upper lip' or something?".

Which is doubly odd, because here that is more associated with upper-middle-classes. That cold stoicism that causes people to act 'gentlemanly' regardless of circumstance, or parents to pressure their children to be upwardly mobile, generals to describe an unwinnable position as "a bit of a pickle" etc. etc.

In Britain this is definitely seen as a class characteristic rather than a climatic one (we all live in a similarly temperate environment).