The euphemism to add on the wind chill has always perplexed me. I don’t mean it in a purely mathematical way, because by adding on what presumably is a negative number, you will naturally end up with a lower value, but more in a way that it just doesn’t sound right. The phrase adding on to me gives the impression that something will increase in value rather than actually reduce or lower it. So why don’t we take off the wind chill? But that doesn’t sound right either. The thing is wind chill is not actually a temperature at all, but an index, although to calculate it we do need the temperature and wind speed. Answers on a postcard to the usual address if you have an answer to this deeply philosophical question.