Drinking fluids is crucial to staying healthy and maintaining the function of every system in your body, including your heart, brain, and muscles. Fluids carry nutrients to your cells, flush bacteria from your bladder, and prevent constipation.

Older adults often don’t get enough fluids and risk becoming dehydrated, especially during summer when it’s hotter and people perspire more. “Older people don’t sense thirst as much as they did when they were younger. And that could be a problem if they’re on a medication that may cause fluid loss, such as a diuretic,” says Dr. Julian Seifter, a kidney specialist and associate professor of medicine at Harvard Medical School. Warning signs of dehydration include weakness, low blood pressure, dizziness, confusion, or urine that’s dark in color.