system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: 'It's not the heat, it's the humidity'

Why does the amount of humidity in the air affect comfort moreso than the temperature?
gpt
A big part of how the body regulates temperature is by sweating.  This is because when water evaporates, it takes some of the heat away with it.

When there's more humidity in the air, there's less opportunity for water to evaporate, so that leads to you sweating, and it taking longer to evaporate & cool you down.  So on top of being just uncomfortably humid & "wet", you're also not losing as much heat from sweat so it feels warmer.