Answer:
Human senses include the ability to detect electromagnetic waves in the 3800-7600 angstrom range, air waves of 15 to 20,000 beats per second, air-borne and liquid-borne molecules of proper size, quantity and configuration, and to generate nerve impulses triggered by objects impinging on body surfaces with enough force
I think thirst or dark colored urine. :)
Answer:
counter question if you get out the shower clean then how does your towel get dirty?