When Is It Too Hot to Play Outside?

Healthy Living

June 30, 2022

Summer memories and the great outdoors go hand in hand. But when the heat index climbs, you might need to head inside and out of the sun. 

Being hot is one thing. Risking your health is another. And in some cases, the line between uncomfortably hot and dangerously hot isn’t so easy to see — or feel — until it’s too late.

Wondering when it’s too hot for you and your kiddos to be out and about? Here’s some general guidance on what’s safe when it comes to summer fun.

What is a heat index, anyway?

The thermometer offers only one measure of the outdoor environment. How hot it feels and how much the heat affects you depends more on something called the heat index.

Heat index is a measure that accounts for both air temperature and relative humidity. When the humidity is high, even moderate temperatures can start to feel oppressive.

For example, on an 84-degree day with 40% relative humidity, there’s a heat index of 83 degrees, meaning it more or less feels the same as what the thermometer says. If the relative humidity rises to 95%, though, the heat index will jump to 100 degrees.

When humidity is high, less sweat evaporates from your skin. That leaves you vulnerable to overheating because sweating is a critical component of regulating your body temperature. 

Take the heat index into consideration if you’re trying to figure out when it’s safe to play outside. If the high is 84 and it feels like 84, that’s not as big of a problem as a high of 84 that feels like 100. 

The heat index measure provides a more accurate picture of outdoor conditions and the precautions you need to take.

Generally speaking, the following guide can help you figure out what’s safer:

  • Heat indexes below 80 degrees are comfortable. 
  • Levels in the 80s are still safe but can become problematic after a while. 
  • When the heat index climbs into the 90s, it’s time to take extra precautions. 
  • An index of over 100 degrees is dangerous and requires extreme caution.

Of course, your age and health status could play a factor here, too. Younger kids and people with health problems might need to be more conservative. 

But even if you don’t have any underlying health conditions or other reasons to avoid the humidity, you might just not like the heat and prefer to stay inside when the index hits the 80s.

Kids and Hot Weather

Children need adult guidance to determine when it’s safe to play outside and when it isn’t. Here are a few guidelines to help you make the right call.

Babies and Toddlers

The littlest kids don’t sweat much. This keeps them from regulating their body temperature as well as older kids and adults can.

Also, little ones can’t let you know when they’re feeling uncomfortable. They may become cranky or fussy, but they won’t be able to articulate why.

In other words, caution is key when it comes to babies and toddlers. They need frequent breaks from the heat and plenty of shade. If you’re feeling hot and sweaty, then your child is probably uncomfortable, too.

Consider helping your baby build up stamina for hot weather. Over a few weeks, introduce your infant to being outside a little longer each day. For safety’s sake, keep your baby hydrated and take frequent cool-down breaks.

A note about hydration in infants: avoid water for your littlest ones and limit it in older babies. 

That’s because infants get what they need from breastmilk or formula. Water can actually be harmful to babies under 6 months old, and they don’t need much between ages 6 months and a year, either. Check with your pediatrician if you have concerns about hydration.

Older Children

As kids move out of the toddler phase, they become better able to tolerate heat. They can also let you know when they’ve become uncomfortably hot.

Just because they can let you know doesn’t mean that they will, though. Children who are caught up in playing may ignore the signs that they’re starting to overheat. Even if you ask, they may deny that they’re uncomfortable. (The same is true of other basic functions, like using the bathroom. Kids need reminders.)

Children also need frequent reminders to hydrate and apply sunscreen. As a caregiver, it’s your job to provide those prompts and to keep an eye on everyone’s status. There may be times when you need to make the call that it’s simply too hot to be outside any longer.

No set rule says you have to bring kids inside once the heat index reaches a certain point. But anytime the measure is 80 degrees or above, you should look out for signs of distress in your kiddos (and yourself). 

And be incredibly vigilant once you get to levels over 100 degrees. In many cases, that may mean staying inside.

Teens, Adults and Athletes in the Heat

Growing up doesn’t make you immune to heat-related illnesses. Extreme weather can cause issues at any age.

General Population

The same guidelines for heat index safety apply to children, teens and adults. Everyone needs to pay attention when the heat index gets over 80 degrees and use extreme caution at 100 degrees or above.

These guidelines may be too generous for people with certain health conditions, though. Keep yourself cooler if you’re overweight or have diabetes or low blood sugar. Adults over 65 should also be cautious.

But no matter your physical condition, the more active you are outside, the sooner you may overheat. 

When possible, save yard work and other physical activity for the cooler parts of the day. That usually means doing those activities before 10 a.m. or after 3 p.m., when the sun isn’t as fierce.

Sports and Exercise

Because you can overheat more quickly when you’re active, athletes need to be extra careful. Heat illnesses during practices or games can lead to injury or even death.

Before participating in summer athletics or exercise, visit the doctor for a physical. Talk to your physician about the risks and benefits of outdoor exercise. Discuss whether there are any special precautions that you or your kids need to take before signing up for a new sport.

Also, avoid outdoor athletics on days when you’re under the weather. When you’re ill, you might not be able to regulate your body temperature as well. Plus, staying home when you’re sick is just good practice (and manners).

Just as you’d do with babies, you can get yourself used to higher temperatures over time. Gradually increase the length of your outdoor exercise sessions. And make sure to give yourself plenty of water and breaks in the shade when possible.

Signs of Overheating

Thirst is a sure sign that you’re getting too hot. Your mouth and lips may dry out as well. When that happens, it’s time to hydrate and cool down. Excessive sweating and overly warm skin are other signs of overheating.

Left unchecked, overheating may lead to illness. There are three levels of heat-related illnesses:

  • Heat cramps. This condition involves flushed skin and unpleasant muscle cramps.
  • Heat exhaustion. At the next level, you might experience fever, nausea, headache or diarrhea.
  • Heatstroke. Someone suffering from heatstroke may stop producing sweat. He may also have an elevated heart rate, confusion and fatigue.

If you notice any of these symptoms, take a rest and hydrate. Opt for sports drinks over plain water to replenish lost electrolytes. A cool cloth can help bring the body temperature back down as well.

Heatstroke is a life-threatening emergency. Call 911 right away if you suspect that someone is suffering from heatstroke. 

While waiting for emergency personnel, remove as much clothing as possible from the person, and cool him off with wet rags and bags of ice.

Tips to Beat the Heat

With caution, you and your kids can play outside even on hot and muggy days. Just be smart about it by taking steps to keep everyone safe, like:

  • Spending time in the shade
  • Taking indoor breaks
  • Wearing lightweight clothes
  • Playing with water, such as swimming pools, sprinklers or water tables
  • Relaxing instead of running around
  • Staying hydrated

Water is good for hydration, but sports drinks can be even better. When you sweat, your body loses salt. These drinks replenish sodium and other electrolytes. Most contain sugar, though, so use them in moderation. Young kids can sip an oral rehydration solution instead of a sports drink. And babies, as we said earlier, can stay hydrated with breastmilk or formula.

Above all, remember that indoors is often best when the heat index soars above 100 degrees. You might be tempted to soak up every drop of sunshine, but it’s okay to miss a few drops in the name of safety.