The second is right. In contemporary use жаркий (short form жарко) is used to describe weather, air temperature and how you feel (for example, if в комнате жарко, you might consider opening a window or going outside to a more chilly place).
Горячий is used to describe the temperature of an object.
About "очень": I think of it as a general enlargement modifier, and as so, something that can be translated to a veriaty of similar words in english, not just "very". In this sentence I tried to test it, by using "extremely", but got rejectem. Am I wrong, or did I just used a word the creators haven't considered?
(Probably it was adressed in one of the many opportunities before, but I don't know where to look.)
I think, right now only "very" and "really" fit that niche in English. "Extremely", "terribly", "immensly", "tremendously" are all nice but очень is a basic intensifier, not a colourful word you use when "very" does not cut it.
As "very" falls out of use another will appear over time.
It is similar to how "good" means roughly the same as "awesome" but you would not treat them the same (at least, if the language you speak lets you express different degrees of awesomeness).