Whether inside or outdoors, your body loses water throughout the day, especially in extreme heat. Staying properly hydrated is critical in Arizona’s high temperatures. Water is the best choice for hydration during hot weather.
Proper hydration helps your body regulate its temperature, eliminate waste and keep your mind functioning well. Not getting enough water can have real effects on your health – when your body becomes dehydrated, you can begin suffering from heat-related illnesses, and if left untreated, it can even lead to death.
It can be hard to know how much water you need to drink throughout the day. You may be dehydrated and not even know it. We’re here to help with some general guidelines you can follow.
The average adult needs at least eight eight-ounce cups (64 ounces) of water per day, which is equal to two liters or half of a gallon of water. Each person’s hydration needs can vary depending on activity level and other factors.
When working in the heat, drink one cup (eight ounces) of water every 15 to 20 minutes (24 to 32 ounces) per hour. Drinking at shorter intervals is more effective than drinking large amounts infrequently. Do not drink more than 48 ounces (1 1/2 quarts) per hour! Drinking too much water or other fluids (sports drinks, energy drinks, etc.) can cause a medical emergency because the concentration of salt in the blood becomes too low. People who are engaging in prolonged or strenuous activities in the heat may benefit from sports drinks with balanced electrolytes.
About 20% of daily fluid intake usually comes from food and the rest from drinks. Eating foods with a high water content can help you stay hydrated too, including watermelon, honeydew melon, cantaloupe, lettuce, strawberries, pineapple, peaches, oranges, cucumbers, bell peppers, broccoli, celery, summer squash like zucchini and yellow squash, and more.
For children playing outside or showing signs of dehydration, encourage them to take eight gulps of water every 15 minutes. Even young and healthy people can become dehydrated. It can happen quickly, especially if they participate in strenuous physical activities in the heat.
When you’re indoors, you should drink at least 64 ounces of water a day. We recommend everyone hydrate often and take frequent breaks when outdoors.
During the hottest days, it’s important to know if you’re at greater risk of heat-related illness. People who may be at a greater heat risk and need more than 64 ounces of water a day include:
- Infants and children.
- Older adults.
- Pregnant and breastfeeding people.
- People in larger bodies.
- People with mental illness and chronic diseases.
- People who do high levels of physical activity.
- People working or exercising outdoors.
- People who take eat-sensitive medications or consume substances including caffeine, alcohol or drugs.
- Sensitivity to thirst decreases with age – those 65 and older should be sure they’re getting enough water or water-rich foods during the day.
Some early signs of dehydration you can look for in your body include:
- Feeling thirsty.
- Dark yellow and strong-smelling urine.
- Urinating little and less than four times a day.
- Feeling dizzy or lightheaded.
- Feeling tired.
- Dark circles and sunken eyes.
- Dry mouth and/or chapped lips.
- Skin that does not go back into place when pinched or pulled.
Pay attention and act when you notice signs of dehydration to avoid heat-related-illness. Always carry water with you and drink even if you do not feel thirsty.
We encourage you to take time this summer to check on your friends and neighbors and ensure they’re safe and have access to clean water. There are free cooling and hydration centers for the public available around the state to ensure all Arizonans can prevent heat-related illness.
Dr. Eugene Livar currently serves as Arizona's first chief heat officer. Appointed to this role in 2024, he oversees the implementation of Gov. Katie Hobb’s Extreme Heat Preparedness Plan. He began his public health work at ADHS in 2012 as an epidemiologist assisting with state efforts covering border health and unexplained deaths.
