It is. I have a friend who lives in Phoenix, where dehidration is a big problem because of the humidity. You don't even notice how much water you are losing through perspiration because it instantly evaporates from your body. They have these special containers that you can buy there. They fill them up with water every day, drink from them, and at the end of they day they should be empty. It's a way to make sure you drink the mnimum amount.