Beat the Heat: Heat Illness in Children

It has been an extremely hot summer so far in all parts of the United States.  Record highs are being set all over the country.  Today we will discuss exertional heat illness in children so you can be better prepared to identify and prevent this in our children as they continue to be active throughout the summer months.

Why is temperature regulation important?

Our bodies are made to function at an optimal core temperature of 98.6°F (37°C).  The “thermal neutral” zone in which we operate is 36.5 – 37.5°C .  When the temperature deviates too much from that, temperature sensitive structures such as body enzymes and other proteins begin to denature, and essential processes start to fail.  Extreme cold slows down metabolic processes and at temperatures below 33°C we lose consciousness.  In extreme heat, temperatures above 42°C are not compatible with life.

How do we temperature regulate?

Even without activity, our body is generating heat at a rate that would increase our core temperatures by over 1°C per hour.  When we are exercising hard, that heat generation can increase 10-fold.  Therefore our bodies are equipped under normal circumstances to dissipate the heat.  The main methods of heat dissipation are: radiation, convection, conduction, and evaporation.  Radiation is the primary way in which heat is dissipated when the skin temperature is greater than air, but when air temperature exceeds the skin temperature, evaporation becomes the primary method of cooling.  This happens in the form of sweating (humans), and panting (dogs).   When normal functions of heat dissipation are not working correctly, or when heat generation exceed heat loss, the body is in danger of a spectrum of heat-related illnesses from heat cramps, heat exhaustion, and heat stroke.

Why are children at greater risk than adults?

Children are more susceptible to heat illness because they have:
1. Greater surface area to body mass ratio
2. Lower rate of sweating
3. Higher temperature at initiation of sweating
4. Slower rate of acclimatization to heat

Tips on beating the heat?

1. Stay indoors or in a shaded area during the hottest part of the day.   Schedule practices or events before 11am and after 6pm.
2. Pre-hydrate!  Dehydration increases the risk of EHI.
3. Hydrate on a regular schedule during and after exercise.  Thirst is a poor indication of hydration status, especially in children.  A good starting point is 4 to 6 ounces of fluid every 15 minutes for a 90-lb child.
4. Check the weight!  Checking your child’s weight before and after exercise will give you an idea if hydration was adequate.  Weight loss of greater than 2.5% indicates dehydration.
5. Get acclimatized.  The body can take 1-2 weeks to get adjusted to the heat, so avoid strenuous practices in the beginning.  Start light and gradually increase.
6. Wear appropriate clothing.  Keep it light on the hottest days.
7. Know the symptoms of heat exhaustion and heat stroke:
Heat exhaustion: Athletes can be sweaty, ashen in color and complaining of weakness, headache, dizziness, irritable, nauseous or vomiting.
Heat stroke: Athletes can have similar symptoms as heat exhaustion, but can also be dry, hot, and flushed, and will also have confusion, delayed response or other change in mental status.  Rectal temperature if taken will be >104°F.
8.If your child has any medical problems that may affect their ability to temperature regulate, discuss with your pediatrician.

What should you do if you suspect heat exhaustion or heat stroke?

1. Get the athlete out of the sun, and indoors or into a shaded area.
2. Oral hydration and cooling with active cooling techniques such as removing excess clothing, drinking cool water, sponging the body with cool water, placing ice pack in the armpits, and groin.
3. Have the athlete evaluated by a medical professional as soon as possible.
4. If there is any change in responsiveness or other mental status change, be concerned about heat stroke.  Call 911 and initiate rapid cooling if possible.

Wishing everyone a safe, happy, and fun summer!