Most experts recommend drinking eight glasses of water per day. This number may not be spot on, scientifically speaking, but it’s not hard to remember, and it’s a good goal. Those living in high temperatures or humid environments need more, as well as those who are exercising. The human body is roughly 60% water, and even slight dehydration can cause fatigue. Water is vital to your body’s waste removal, temperature regulation, joint protection, and many other key needs.