Infants and toddlers are not small adults where heat is concerned. They have a higher surface area relative to body mass, so they gain heat from the environment faster. They sweat less effectively. Their thirst response is less reliable and they often cannot ask for water. And a child under three cannot tell you they feel dizzy, or remove their own layers, or move to shade on their own.
That combination means the thresholds that work for adults are not conservative enough for a daycare, and that the supervising adult has to be doing the monitoring that an older child would do for themselves.
Outdoor play guidance by WBGT
There is no national standard for childcare specifically, so these are conservative thresholds derived from pediatric heat guidance. Your state licensing requirements take precedence where they exist.
| WBGT | Infants under 1 | Toddlers 1 to 3 |
|---|---|---|
| Under 80°F | Normal outdoor time, shade and fluids available | Normal outdoor time, shade and fluids available |
| 80 to 84.9°F | Shaded areas only, 30 minutes maximum, offer fluids every 15 min | Shade available, 45 minutes maximum, offer fluids every 15 min |
| 85 to 87.9°F | 15 minutes maximum, full shade, or keep indoors | 30 minutes maximum, shade only, quiet play |
| 88 to 89.9°F | Indoors | 15 minutes maximum in full shade, or indoors |
| 90°F and above | Indoors | Indoors |
These are deliberately more conservative than adult or athletic charts. A reading that permits a modified football practice is not a reading that permits an infant outdoors.
Check the surfaces, not just the air
This is the hazard most specific to young children and the one most often missed. Playground surfaces can burn skin while the air still feels tolerable.
- Touch metal and plastic equipment with the back of your hand before children use it. If you cannot hold it for five seconds, it is too hot.
- Check slides, climbing frames, handrails and anything dark or metal. These reach the highest temperatures.
- Check rubber safety surfacing and artificial turf, which can run far above air temperature and sit directly under crawling children.
- Remember that a child who falls lands hands and knees first on the surface.
- Shade cloth over equipment reduces surface temperature substantially and is worth the cost.
What supervising adults should do
Offer fluids actively
Do not wait for a child to ask. Offer water every 15 minutes during outdoor time in the heat, and more often for toddlers who are active.
Use shade deliberately
Shade is not a nice extra. Plan outdoor time around where the shade actually is at that hour, not where it was in the morning.
Shift the schedule
Move outdoor time to early morning during hot weather. Late morning and afternoon are the worst of the day and the WBGT peak is later than people expect.
Never leave a child in a vehicle
Interior temperatures rise dangerously within minutes even with windows cracked and even on days that do not feel hot.
Heat illness in young children
Children present differently from adults, and the early signs are behavioral rather than dramatic. Any of these in the heat means move indoors and cool down now:
A child who is unusually sleepy, limp, confused or stops sweating in the heat needs emergency care immediately. Call 911, move them indoors or into shade, remove extra clothing and begin cooling with cool water on the skin while you wait. Do not wait to see whether they improve.
Check before outdoor time
The free WBGT app shows the real heat load for your location, not just the air temperature, and forecasts it hour by hour so outdoor time can be scheduled for the cooler part of the morning.
- Real-time WBGT for your location
- Hourly forecast to plan outdoor time
- Humidity, sun and wind behind the number
- Free on iPhone
WBGT is estimated from weather data with the peer-reviewed Liljegren model. Where a policy requires on-site measurement, use the app for planning and as a cross-check alongside your instrument.
Common questions
What temperature is too hot for daycare outdoor play?
Air temperature alone is not a good guide because humidity and sun change the risk substantially. Using WBGT, infants should generally stay indoors above about 88°F and toddlers above about 90°F, with shortened shaded time well before that.
Why do infants overheat faster than adults?
They have more surface area relative to body mass so they absorb environmental heat faster, their sweating is less effective, their thirst response is less reliable, and they cannot remove clothing, seek shade or ask for water on their own.
How hot can playground equipment get?
Dark metal and plastic equipment in full sun can exceed 150°F and in some cases approach 180°F, hot enough to cause contact burns quickly. Always check surfaces with the back of your hand before children use them.
How often should toddlers drink water outside in the heat?
Offer fluids every 15 minutes during outdoor time in hot weather rather than waiting for a child to ask. Young children often do not recognise or communicate thirst until they are already behind.
What are the signs of heat illness in a baby?
Unusual fussiness or sleepiness, flushed or hot skin, reduced sweating, refusing fluids, fewer wet diapers, rapid breathing, vomiting or a limp and unresponsive child. Any of these in the heat needs immediate cooling and medical attention.
Related WBGT guides
Know the real heat number
Real-time WBGT, flag levels and forecasts. Free on iPhone.
