Heat cramps: Sweating a lot during strenuous activity can deplete the salt level in muscles, which can lead to painful muscle cramps.

Heat exhaustion: This can develop after exposure to high temperatures for several days without adequate hydration. Warning signs include heavy sweating, paleness, headache, fainting, dizziness, or heat cramps.

Heat cramps and heat exhaustion will usually resolve once you move to a cool place and start drinking water or a sports beverage, but seek medical attention if symptoms don’t resolve in one hour.

Heat stroke: This is a more severe form of heat-related illness that requires immediate medical attention. Call 911 if anyone, especially a young child or an older person, is showing these symptoms: