How can a sweating person maintain their water balance?

How can a sweating person maintain their water balance?

The kidneys can regulate water levels in the body; they conserve water if you are dehydrated, and they can make urine more dilute to expel excess water if necessary. Water is lost through the skin through evaporation from the skin surface without overt sweating and from air expelled from the lungs.

i am going to guess that it is co2.