i mean it doesnt have to be anime conventions its usually any kind of gathering where said yopic. of convention has a gathering of introverts, in particular, ones that have 0 sense of self awareness.
in terms of worst to less worse:
Card game tournament(sweaty, generally lack of AC, small venue cause cheap) < Video Game tournament (similar but in a room full of electronics, usually helped out by that their venue is larger) < anime conventions
ofc the cosplays have an effect as well, but theyre typically the minority at a convention vs those playing TCGs or Video games, who are often the majority.
the triple threat funny moment was San Jose 2016. Genesis 3 (Super smash bros tournament) took place at the same time and venue as Furcon, as well as a female volleyball tournament, all 3 generating sweat differently.