Is it related to the heat that it gets generated at the concerts?
Context:
Most of the time when there's an event I see some women only having a bra on, others have some type of swimsuit or a one piece swimsuit (or wearing clothes similar to it).
They seem to be happy like that or they don't care of what people think about their outfit. But what I wonder if they're ok during the cold times (some of the days these concerts occur are when temperatures are on the 50 - 60s). And they don't seem to mind everybody looking at her (specially guys looking at women with revealing clothes).
It's curious.