The air in a room is relative to the temperature of that room. If it’s too hot, people sweat more. It would be like walking around outside on a 90 degree day and sweating profusely – you’re essentially transferring heat from your body into the air through evaporation. In colder weather, people tend not to sweat as much because their bodies have an easier time retaining heat so they don’t need to release any moisture from themselves or brush against cold surfaces as often. As I said above, there are some other factors at play here but this mechanism by which we cool ourselves down is one of them!