As kids head outdoors to participate in sports or spend a day of fun in the sun, it’s important to keep them hydrated and cool to avoid dehydration and other serious heat-related injuries.

“Because children’s body surface area make up a much greater proportion of their overall weight than that of adults, they are at greater risk of dehydration and heat-related illness,” says Dr. Albert C. Hergenroeder, chief of Texas Children’s Sports Medicine Clinic and professor of Pediatrics at Baylor College of Medicine.

Children who compete in sports or those who spend a lot of time outdoors in the heat without proper rest and fluid intake are more vulnerable to dehydration.

“Once children become dehydrated, their body temperatures rise very quickly, especially when exposed to high temperatures and humidity,” explains Hergenroeder. “Dehydration can lead to serious conditions such as heat exhaustion and heat stroke, both of which can result in death.”

Though thirst is a symptom of dehydration, it is not a reliable indicator of the need to drink more fluids, especially for young children who are busy playing and those with special health care needs.

Other symptoms of dehydration include (for infants up to adolescents, so not all apply to each age group):

• Few or no tears when crying
• Eyes that look sunken into the head
• Soft spot (fontanel) on top of baby's head that looks sunken
• Lack of urine or wet diapers for six to eight hours in an infant (or only a very small amount of dark yellow urine)
• Lack of urine for 12 hours in an older child (or only a very small amount of dark yellow urine)
• Dry, cool skin with “goose pimples” on chest and upper arms
• Irritability
• Altered mental status
• Headache
• Fatigue or dizziness in an older child

To protect children from dehydration, Hergenroeder says parents should encourage them to drink water before, during and after outdoor activities. The colder the water, the faster it is absorbed. For example an adolescent should drink one to two cups of water two to three hours before going out, then one to two cups of water every 20 to 30 minutes while exercising in the heat.

“Parents should avoid giving children fruit juices, sodas and other caffeinated and carbonated beverages,” says Hergenroeder. “These types of drinks can actually make dehydration occur more quickly.”

He also advises parents to keep kids in the shade as much as possible and dress them in light-colored, loose-fitting, cotton-blended clothing.

For children who will be outdoors practicing or playing summer sports, Hergenroeder suggests they begin spending time outside before practices or activities begin in order to acclimate to the heat – a process that can take 10 to 14 days.

“If parents suspect their child is becoming dehydrated, they should take him or her to a cool, shaded area and begin giving the child cold water to drink,” he says. “If the child becomes unconscious or appears confused or exhausted, has noticeably dry skin or his or her body temperature continues to rise, dial 911 or take the child to the nearest emergency room for immediate treatment.”