Several have asked about the impact of dehydration on the brain, especially in light of the unusually high temperatures that recently have been occurring in various parts of the world. Estimates are that this planet is approximately 75% water and 25% solid matter and many individuals recognize the potential dangers that may result when that ratio is altered by severe weather. The human body consists of approximately the same ratio—but many people do not seem as cognizant of what happens when that ratio is altered. Personally, I find the topic of dehydration very interesting. It may be the ultimate stressor for the human brain. The brain is the first body system to recognize a stressor and it responds with nanosecond speed to trigger the stress response. More tomorrow.