Mate I have to reply to that, because it's such an insane claim - the US, the only country that doesn't use °C, has this huge reliance on a monstrously complex credit system (obviously the entire concept of credit is reliant on the concept of debt and negatives). It's flat out insane to suggest that the same people who live and function with such a credit system conceptually struggle with the fundamentals negative numbers. It's a mind boggling claim.
Anyway, have a good one.
Why do yanks insist picking such idiotic numbers when they speak in metric, seriously wtf is -18 to 38? If those were realistic temperatures, surely you realize it would be -20 to 40, no?
-20, or any negative c, is rare to most ff the worlds population so your comment is dumb on two fronts.