Excessive heat warnings and heat-related illness

Extreme heat is serious business — it’s the leading causeOpens in a new tab of weather-related deaths in the United States each year. Heat alerts are also linked to higher risksOpens in a new tab of fluid and electrolyte disorders, and heatstroke.

So if you see an “excessive heat warning” pop up in your weather app, you’ll want to be prepared to stay cool and stay hydrated. You may also want to stock up on certain supplies, and keep an eye on loved ones.

To stay cool, it helps to have water, electrolytes, and cool towels on hand, and to stay out of the heat. These suggestions may sound common-sense, but I often hear confusion about the hydration piece in particular. One of these misconceptionsOpens in a new tab is that more water is always better, which can actually lead to overhydration and make you feel worse. The quick tip on the hydration front is to drink electrolyte water to thirst, to replenish both the electrolytes and fluids you’re losing in sweat.

Hydration is just a part of what we’ll talk through today. We’ll walk through tips to prepare for extreme heat, define heat cramps, heat exhaustion, and heatstroke, and cover what the various heat alerts you may see mean. Let’s dive in.

What Is an Excessive Heat Warning?

An excessive heat warning is one of the most urgent heat alerts issuedOpens in a new tab by the National Weather Service. Here are the alerts you may see, in ascending order of urgency:

1. An excessive heat outlook warns of dangerously hot conditions in the next 3-7 days
2. An excessive heat watch warns of dangerously hot conditions in the next 24 to 72 hours
3. An excessive heat warning warns of dangerously hot conditions in the next 12 to 24 hours
4. A heat advisory warns of dangerously hot conditions in the next 12 hours

How hot is dangerously hot? The criteria vary by county, but you’re typically looking at temperatures north of 100℉. Humidity also factors inOpens in a new tab.

The Dangers of Hot Weather

Possible dangers from the heat include fluid and electrolyte imbalances, heat cramps, heat exhaustion, and heatstroke. Older folks and infants tend to be more vulnerable to the heatOpens in a new tab.

Let’s review each of these potential dangers. 

#1: Fluid and electrolyte imbalances

Hot weather can lead to fluid and electrolyte imbalancesOpens in a new tab — including dehydration, overhydration, and low sodium levels — that can affect many critical organs, including the brain.

Part of this problem may stem from hydration confusion. Many folks think drinking more water is always better, but the evidence suggests that over-hydrating with plain water beyond thirst can dilute blood sodium levels and impair nervous system functionOpens in a new tab, among other issues. Learn more about these imbalances hereOpens in a new tab.

Fluid and electrolyte imbalances can also contribute to the following three dangers.

#2: Heat cramps

Heat cramps are a type of muscle cramp. The term “heat cramp” is a little misleading, because they’re often triggered by water and sodium lossesOpens in a new tab due to increased sweating from the heat, and not the heat directly.

For a deeper dive, check out this articleOpens in a new tab on preventing heat cramps. 

#3: Heat Exhaustion

Prolonged exposure to high temperatures can causeOpens in a new tab a form of heat stress called heat exhaustion. Symptoms of heat exhaustion can include:

• Nausea
• Cold or clammy skin
• Excessive sweating
• Tiredness
• Dizziness
• Headache
• Muscle cramps
• Fainting

The most common suggestion for heat exhaustion is to rest in a cool room while rehydrating, but be sure to seek out medical attention, too. Read this articleOpens in a new tab to go deeper. 

#4: Heatstroke

HeatstrokeOpens in a new tab is the most serious heat illness. When someone has heatstroke, their body temperature can exceed 104℉. The symptoms are comparable to heat exhaustion but more severe.

If you suspect you or a loved one has heatstroke, call 911 and seek trained medical help. The pros will help with cooling and rehydration. Here’s an article on heatstrokeOpens in a new tab to learn more.

Okay, so your weather provider is warning of extreme heat. How should you prepare for it?

Preparing for and Dealing With Heat

If heat is in the forecast, it’s wise to be prepared. Here are some tips to keep in mind. 

#1: Stay cool

Most days, I’ll choose outdoor activities vs. indoor activities. But when you see a heat alert, it’s worth reconsidering. Can you move your jog to the early morning when it’s 20 degrees cooler? Do you have an air-conditioned gym nearby?

The late spring and early summer are also excellent times to ensure your air conditioning is working properly. If you don’t have A/C, consider installing it. If that’s not an option, think about hanging out in places with A/C (mall, store, gym, etc.) on sweltering days.

If you find yourself overheating, it can help to move to a cooler location, put a cool, wet towel on the back of your neck, sit down, and let your body cool off. And if you’re worried about heat-related illness, you may want to seek medical help. 

#2: Stay hydrated

A simple guideline to help stay hydratedOpens in a new tab is to drink electrolyte water thirst.

The electrolytes are the part of the equation many folks miss. When you sweat, you lose both water AND electrolytes (especially sodium). Drinking electrolyte water helps replace both losses and prevent symptoms of fluid and electrolyte imbalances. Learn more about sweat loss and how to replace it hereOpens in a new tab.  

It’s worth noting that people can still develop heat illnesses while properly hydrated. In other words, hydration isn’t a shield against extreme heat, but rather helps your body deal with heat by allowing you to sweat and cool yourself and keeping bodily fluids in balance. The suggestion to stay cool still applies, folks!

Your hydration strategy will also depend on your day’s plans. Are you planning on golfing, runningOpens in a new tab, or hiking on a scorcher? Pack accordingly. 

#3: Stay stocked

Like other weather events, heat waves may occasionally affect the supply chain. Consequently, it’s wise to store 1-2 weeks of emergency supplies that require no refrigeration during a potential power outage (canned goods, bottled water, electrolytes, etc.). Better safe than sorry.

#4: Stay vigilant

If you’re caring for people, animals, or even yourself during extreme heat, here are some tips that can help: 

• Don’t leave a person or animal unattended in a car
• Keep hydration with fluids and electrolytes in mind
• Think about access to A/C, reducing outdoor activities, and other ways to stay cool
• Monitor for signs of heat-related illness

These are some things you can do yourself, but remember that trained medical professionals are best equipped to handle heat illness. 

Feel free to bookmark and revisit this article next time a heat alert pops up in your weather app. Thanks for reading.