U could be dehydrated or u could have just been doing something physical and u wer breathing really hard and it could also be bcus of breathing through ur mouth.
its the body's response that you need to drink cous it cant produce enough ........... maby ? ;] ?
are you thirsty? if not you probobly should eat a mint or somethig like that, I do that.
well you might need to drink more liquid or you might be getting sick!
Are you breathing dusty air or dry air out of an air conditioner?
might be getting a cold drink lots of fluids
your probably dehydrated.