Water is a must when temps are soaring, and people are spending more time outside. While we already know that dehydration can induce symptoms akin to a hangover – sluggishness, headaches, crankiness, nausea – new research shows that staying hydrated has another surprising benefit. Drinking water can aid memory, and increase reaction time. The study, published in Frontiers of Human Neuroscience, compared the test performance of two groups of people, one given water, and the other deprived. When tested on memory, attention, learning and reaction-time, the hydrated group received better scores with 14% faster reaction times. So next time you’re feeling out of it in the afternoon, try drinking a tall glass of ice water before you reach for your coffee.