Another July 4th is coming. Another wave of heat is set to swallow the central and eastern US. We are talking 90s. We are talking low 100s for multiple days straight.
Add humidity into that mix? The heat index could climb to 115 F. It feels like an oven inside your lungs.
This isn’t just uncomfortable. It’s lethal. In 2023 — one of the hottest years recorded — researchers tied that sweltering air to more than 2,390 deaths. Nearly 120,00 more people ended up in emergency rooms dealing with heat sickness.
Why?
“What makes extreme heat most dangerous for people it is that it is invisible. With extreme heat you might not immediately some risks you navigate day” – Kevin Kelley, American Red Cross.
You don’t see the threat coming. You walk through your day until your body quietly gives out.
The biology of overheating
Daniel Smith PhD at Emory University sees it differently. He thinks heat makes us confused. We stop reacting to our own bodies. We ignore the signals that we are too hot.
The result is acute heat exposure. Your heart takes a severe stress hit. Dehydration strains the cardiovascular system. If this keeps happening, if the body stays dehydrated for long periods, the kidneys can fail. It happens in the long run, silently, until it’s not.
Who suffers the most
Everyone can die from heat. Some of us are just easier targets.
Your body has a hard time staying cool if you are older. Smith notes older adults often don’t feel thirst until it’s too late.
Kids? They heat up faster than we do.
Pregnant people? Higher demands on their cardiovascular system makes things risky.
People with chronic illness or disabilities are vulnerable too.
So are those who work outside. Athletes, laborers, anyone stuck under the sun all day.
And don’t forget what’s in your medicine cabinet. Your pills can turn against you in high heat.
- Antihistamines and decongestant cut sweating. Your body loses its ability to cool down.
- Beta-blockers reduce blood flow to the skin. Self-cooling fails.
- Diuretics drain your total body fluid.
- Psychiatric drugs — antidepressants, mood stabilizers, stimulants — change how your brain handles stress signals. Heat becomes a shock your system isn’t ready for.
- GLP-1 drugs for weight loss? They reduce hunger signals. By extension they lower thirst cues too. You won’t want to drink until you already should have.
Get ready before the sun burns you
Kevin Lanza PhD at UTHealth Houston says you need a plan. Now. Not when the thermostat reads triple digits.
Stay informed. Check forecasts. Look at heat indices — the number that matters more than raw temperature. Turn on weather alerts. Download apps like Red Cross Emergency or the OSHA Heat Safety tool. Real time warnings help.
Hydrate aggressively.
“Folks are chronically dehydrated – not getting water enough begin with” – Lanza
Other liquids work for some but avoid caffeine. Avoid alcohol. They pull water right out of you.
Check your AC unit. Does it work? If your power goes out — which extreme heat can cause — you need backups. Cool medication storage, charged devices.
Find your sanctuary.
Schools. Libraries. Malls. Rec centers. They often become cooling stations. Know where yours are before you need one.
Build a network. Call friends. Neighbors. Check in on them. People who are connected socially are much more likely survive. Loneliness kills during heat waves.
Survival mode: what to do now
If you’re out there.
Drink water. Every hour. A full cup. Even if you don’t want to. Say no to sugar, no to caffeine, no to alcohol.
Find air conditioning. Get into a cold room. If home is an oven go to a cooling center. Take a cold shower. Dress in loose, light colors. Cotton, linen. Whatever lets the skin breathe.
Time your movement. Don’t be outside during the peak hours. If you must work outside Smith says you might need 30 minutes off for every hour worked. Depending on the intensity of your job. That’s not laziness. It’s physiology.
Stay connected. Help others. Check your pets. They don’t know to look for shade either.
When things go wrong
Two big things can happen: heat exhaustion and heatstroke.
Smith sees them as one thing on a timeline. Exhaustion comes first. It’s mild. Heatstroke comes next.
The end state of heatstroke? Death.
Stop believing you stop sweating when you have heatstroke. Some people sweat. Lots of them do.
Signs of heat exhaustion.
You need to stop. Just stop. Rest in a cool spot. Sip water slowly. Don’t gulp it if you feel sick to your stomach. Loosen your shirt. Put a cool wet cloth on your skin. If it gets worse or you vomit or feel your heart racing call for medical help.
Signs of heatstroke.
Call 911 immediately. Move them to the cool. Take off the extra clothes. Get them wet. Put them in a cold bath. Cool them down fast.
Don’t let them drink. If someone is in heatstroke they might swallow air. It could make things worse. Just cool them and wait for the ambulance.
The threat grows
This is not going away.
Climate change is making this worse. The frequency is increasing. The areas are spreading.
Kevin Kelley points out places that never saw this before are seeing it now. Pacific Northwest. Even Alaska.
States that were always hot? They just got hotter.
The South and Southwest lead the charts. Florida has the most cases. Why? Outdoor workers. A massive population of older folks who struggle with the heat.
Temps going over 100 F? Routine there.
