Hot weather can create more than dehydration. Sweating causes water and sodium loss, while heat-related vasodilation can lower blood pressure. Add alcohol, medications, poor food intake, or excessive plain water and the result may be orthostatic dizziness, hyponatremia, instability, and falls. Learn why older adults are especially vulnerable, which medications increase risk, when electrolyte replacement may matter, and which symptoms require urgent medical evaluation.

Extreme heat and prolonged sweating cause the body to lose more than water. Sodium losses during hiking, exercise, gardening, landscaping, and outdoor work can become substantial. Learn how much salt may be lost through sweat, when water alone is sufficient, when electrolyte replacement becomes important, why drinking too much plain water can also be dangerous, and which symptoms mean it is time to stop self-treatment and seek medical care.