Hydration and active kids: Important information for parents and coaches

By: Kendy Vierling, Ph.D.

Staying hydrated in the Arizona heat can become a challenge, especially for kids. Children are not able to adapt to the hot weather as well as adults do and are more likely to become dehydrated for a variety of reasons. For example, children produce more heat when they are active, sweat less, are not able to cool themselves as efficiently, and are less likely to drink enough water during physical activity compared to adults. However, there are ways that parents and coaches can prevent kids from becoming dehydrated or suffering from other heat-related illnesses while still allowing kids to enjoy physical activities.

The dangers of dehydration
Perspiration (sweating) is the body’s way of cooling itself. Therefore, it is important that children drink a lot of water to replace the fluid lost to perspiration and urination. Most heat-related illnesses are associated with dehydration, which occurs when children do not replenish body fluids lost through perspiration and the body does not have enough water to carry out its normal functions. Even a slight imbalance can cause serious problems because water is essential to maintaining proper health and it forms the basis for all body fluids. Mild dehydration (as little as a 1-2 percent loss of body weight) can cause fatigue and dizziness. Although mild dehydration can be reversed by increasing the child’s intake of fluids, severe dehydration (typically defined as a loss of 9-15% of body weight) is a serious medical emergency and requires immediate medical treatment.

Children may be more susceptible to becoming dehydrated and suffering from a heat-related illness if they:

Drink caffeinated beverages or takes medications that can cause dehydration (such as antihistamines or diuretics)
Are rarely physically active
Are at-risk for overweight or overweight
Have had a previous heat-related illness
Participate in physical activity at a level that exceeds their capabilities
Have had a recent illness that caused vomiting or diarrhea

Warning signs and symptoms of dehydration
Although thirst is an indicator of dehydration, it is not an early warning sign and children often “don’t feel thirsty.” By the time the child is thirsty, he or she is already dehydrated. Other symptoms of dehydration include:

Having a “dry or sticky” mouth
Producing less urine or urinating infrequently
Feeling “dizzy” or lightheaded
Producing dark yellow urine
Feeling lethargic or irritable
Having flushed cheeks
Having stomach or leg cramps

Preventing dehydration and heat-related illness
The amount of water that each child needs to drink depends on his/her physical condition, activity level, location, and physiology. It is important to encourage children to stay hydrated and listed below are some tips to ensure that your young athletes are able to enjoy being active when the temperature outside rises, while staying healthy.

Talk to your pediatrician if your child has a chronic medical condition or takes medication. Certain conditions and medications (such as antihistamines or diuretics) can make children more susceptible to heat-related illnesses. Consult your pediatrician to determine how the condition or medication affects your child’s hydration levels or ability to be active in the heat.
Encourage children to frequently drink water with meals and between meals, rather than carbonated or caffeinated drinks. A child should aim to drink 8 to 10 ounces of water every 20 minutes if he/she is participating in outside activities. In addition, children should drink either water or an electrolyte-containing sports beverage 20 minutes before, during and after physical activity. However, some sports drinks contain a large quantity of sugar and calories, so drinking water or diluted sports drinks are often the best fluid replacement choices. It can be helpful to send your child to the practice, game, or activity with his/her own bottle of cool water to drink and refill. If your child does not finish the water bottle during the activity, encourage him or her to drink water afterwards. Children should avoid caffeinated beverages such as coffee, tea, soda, or energy drinks because they speed the excretion of water from the body.
Develop healthy lifestyle habits. Children should be encouraged to eat a well-balanced diet, drink enough water to keep his/her urine clear or light yellow, be physically active, and sleep at least eight hours per night. In addition, children should wear sunscreen because having sunburned skin decreases the body’s ability to cool itself.
Plan when children are active outside and be more cautious that children do not become overheated or dehydrated during the peak heat times. Avoid being active outside during the peak heat times. It is the hottest outside between 10am and 4pm in Arizona, so either plan indoor activities during this time or bring plenty of water to hydrate.
Wearing the proper clothing. Children should wear light colored, loose-fitting clothing, preferably of a breathable fabric that allow air to circulate near the skin or that reflect the sun’s rays. If the clothing becomes drenched with perspiration, they should change into clean, dry clothing.
Help children acclimate to the heat and Arizona’s climate.
- Help children seek shade to rest. Slowly increase the amount of time that they are active outdoors while giving them the option to rest in the shade if they are becoming overly heated. The temperature in the shade of a tree can be up to 10 degrees cooler than being in direct sunlight.
- Encourage children to hydrate, even if they “don’t feel thirsty.” Arizona’s climate is typically quite dry and lacks a substantial amount of humidity, so be sure to encourage the children to hydrate regularly. Often times perspiration will evaporate from the child’s body so quickly that he/she might not even realize that he/she has been perspiring.
- Prepare for summer humidity. Arizona often becomes more humid during the summer “monsoon season,” so extra precautions need to be taken in humid weather because it is more difficult for the body to cool itself by perspiring. Perspiration needs to evaporate to cool the body, so extra humidity inhibits evaporation and cooling.

With proper preparation, parents and coaches can help kids enjoy outdoor sports and physical activities while preventing kids from becoming dehydrated or suffering from other heat-related illnesses. Click here for healthy sport information fact sheets, archived healthy sport feature articles, or healthy lifestyle information.