At Chicago's 2008 Lollapalooza summer music festival. It was a hot day.
I was wearing a short-sleeved polo today, apparently a rather chilly spring day (10-14° C/50-60° F), which most of my students found rather surprising and brave of me. Some said I was "young" and "strong", implying that young folks like me have a different concept of weather than folks like them. However, one student in particular (a typical middle-aged or elderly Japanese mother or grandmother (somewhere between 35 and 65) who looks and dresses like she's in her late twenties) saw my outfit and said: "Eeeeehhhh?! (a typical Japanese expression of surprise, with rising inflection, sounding like a very long letter "a") You... look... hot."
Now, I'm pretty sure she meant something like: "Honorable teacher, you appear to be clothed for a day of warm weather." But Japanese-to-English translation being the difficult task that it is, what with English's rampant idioms/clichés/phrasal verbs/slang/irregular verbs/et al ... I totally understand her statement. However, there were a number of things that made her statement funny and interesting.
First of all, saying "you look hot" when I'm wearing a short-sleeved polo on a 'cold' day is a bit odd, because it implies that I'm showing physical signs of having a high body temperature (such as sweating, which I wasn't), even though I was under-dressed.
Therefore, "you look cold" makes more sense.
Secondly, "hot" has many different meanings in English, and in that context, this otherwise innocent "you look hot" statement becomes an instantly recognized compliment or come-on for native English speakers:
"You look hot." = "You look sexy/attractive/beautiful/pretty/handsome."
So the appropriate native response in this case would be "Thank you very much! or ... Domo Arigatou Gozaimas!"
Anyway, I spent the next several minutes explaining all the different meanings of 'hot' that I could think of... here's what I could recall from today:
Hot food = spicy food like the hottest curry in Tokyo.
Hot item = popular item like the hottest Christmas toys of 2009.
Hot person = popular person like Hollywood's hottest young stars of 2009.
Hot team = a team that has won all or many of their recent games, something also known as a 'hot streak'.
Athletes (especially basketball players) are sometimes described as having a 'hot hand' or 'being hot' when they score many points or baskets in a row. 'Hot hand' is also used to describe a gambler at the head of a craps table who is winning a lot of money.
Hotshot = someone who acts very confident or arrogant, see HotShots! (1991 movie spoof)