Heatstroke in babies and toddlers

Why babies overheat faster

Three physiology facts make heat dangerous for small humans:

• Lower sweat efficiency. Babies have fewer functional sweat glands and their nervous system doesn't trigger sweating as effectively as an adult's.
• Higher surface area to body mass. Heat enters from the outside faster relative to body size.
• Less ability to communicate. A toddler can't say "I am overheating." A baby cries, which is also their response to hunger, gas, fatigue, and most things.

The result: a baby in a 95-degree car gets to a dangerous body temperature in 10 to 15 minutes. An adult in the same car has hours before it becomes dangerous.

The two-stage warning system

Stage 1: Heat exhaustion (call pediatrician, cool quickly)

• Flushed face and ears.
• Irritability or unusual fussiness.
• Increased thirst (for older babies) or refusing feeds (younger).
• Damp clothing if the baby has been sweating.
• Skin that feels warmer than usual.
• Decreased activity, slower play.
• One to two fewer wet diapers than usual over 4 hours.

Stage 2: Heatstroke (call 911, start cooling)

• Hot, dry skin. No sweating despite the heat.
• Rectal temperature 103 or higher.
• Rapid, shallow breathing.
• Confusion, severe sleepiness, or hard to wake.
• Vomiting.
• Sunken fontanel (the soft spot looks dipped in).
• No wet diaper in 8 hours.
• Pale or bluish color.
• Seizure.

The transition from stage 1 to stage 2 can be minutes. Treat any combination of stage 1 signs as serious and start cooling now.

The cool-down protocol

1. Move to a cool, shaded place. Indoors with AC if possible.
2. Remove extra clothing.
3. Cool with damp cloths on the head, neck, armpits, and groin. Lukewarm water, not ice water.
4. For older babies, offer cool fluids. For breastfed or formula-fed, offer extra feeds.
5. Skip ice baths for babies. Cooling too fast causes shivering and other complications.
6. Call the pediatrician for any stage 1 signs.
7. Call 911 for any stage 2 signs.

The car-seat trap (this kills children)

The leading cause of pediatric heatstroke deaths in the US is being left in a parked car. Most cases involve a routine change to the morning drive (different parent, different sequence) and a sleeping infant who was forgotten in the back seat.

Prevention:

• Phone or wallet on the floor of the back seat. You won't leave the car without checking back there.
• A stuffed animal in the front passenger seat when the baby is in back. Visual reminder.
• Calendar event for daycare drop-off, with a "no drop-off recorded" follow-up call rule from the daycare.
• Look before you lock. Open the back door every single time you park.
• Talk to your daycare about a call-if-no-show rule.
• Cars with rear-seat reminder systems. Many newer cars have them. Don't disable.

Cars heat up by about 20 degrees in 10 minutes. Cracking a window does almost nothing. Shade in a parking lot does almost nothing. The interior of a car in 75-degree weather can hit 100 degrees within 10 minutes and 120 within an hour. There is no safe parking situation for a baby.

The "cozy cover" problem

Pull-on car-seat covers and after-market footmuffs that wrap around the baby in the seat can dangerously raise body temperature during a drive. Most pediatric organizations recommend removing them once you are in a heated car. Use a blanket over the top of the harness (which you can remove easily) instead.

Outdoor day rules

• Avoid direct sun between 10 AM and 4 PM.
• Hat with brim and back-of-neck coverage.
• Light, breathable, UPF-rated clothing.
• Stroller shade extension. Don't drape a blanket over the stroller, which traps heat.
• Offer feeds more often than usual.
• Check the baby's neck, back, and chest with your hand every 20 minutes. Warm but dry is fine. Hot or sweaty means cool off now.
• Pop-up shade tent for beach or park.

Inside the house

Indoor heatstroke is real, particularly during heatwaves in homes without AC. The plan:

• Move the family to the coolest room.
• Cool baths or sponging through the day.
• A fan blowing across a wet towel works as a low-tech swamp cooler.
• Check on babies napping in carriers or strollers indoors. Carriers concentrate heat.
• If your area expects 90+ for several days and you don't have AC, find a cooling center, library, mall, or relative for the worst hours.

Hydration in the heat

Under 6 months: offer more frequent breast or bottle feeds. Do not give water. Younger infants given water can develop hyponatremia.

6 to 12 months: offer extra feeds and small sips of water (a few ounces per day total).

Over 1 year: water freely, milk as normal. Plain water is the best hydration option. Juice and electrolyte drinks add unnecessary sugar for hydration purposes; reserve electrolyte solutions for illness with vomiting or diarrhea.

If you have to drive in extreme heat

• Run the AC for 5 minutes before strapping the baby in. The car-seat fabric can be hot enough to burn.
• Check the harness buckle with the back of your hand. Metal buckles can hit 110+ in the sun.
• Use a sunshade for the window the baby faces.
• Plan errands for cooler hours of the day.
• Never leave the baby in the car. Bring them with you. Always.