When the grid goes down during a summer heatwave, cooling off isn’t just about comfort—it becomes a matter of survival. Without air conditioning, fans, or refrigeration, the risk of heat exhaustion or heatstroke increases dramatically, especially for children, the elderly, and those with health conditions.
As preppers, we plan for winter freezes and power outages—but extreme heat can be just as deadly. Here’s how to keep your body, your home, and your group cool when the power’s out and the sun won’t quit.
1. Prioritize Shade and Shelter
Keep out of the sun as much as possible during peak heat hours (10 a.m. to 4 p.m.). Set up shaded outdoor areas using:
- Tarps strung between trees or poles
- Reflective emergency blankets (Mylar) positioned above shelters
- White sheets or canvas canopies to reflect sunlight
- Natural shade under trees or rock formations if bugging out
If you’re sheltering indoors, close curtains or hang blankets over sunny windows. Darken the house during the day and ventilate it at night when temperatures drop.
2. Maximize Ventilation Without Electricity
In the absence of powered fans, use natural airflow strategies:
- Open windows at night to let cooler air in.
- Close them during the day and seal off sunlit rooms to trap the cool air.
- Build ventilation towers with vertical chimney-style airflow using black-painted pipe in sunlight to pull hot air upward and out.
- Construct or use manual fans—a stiff piece of cardboard or fabric panel waved consistently can provide relief.
3. DIY Cooling Techniques That Work
Evaporative Cooling (“Swamp Cooler” method)
- Soak a towel or shirt in water and hang it in front of a window or in a breeze.
- Place damp cloths or sponges on the back of the neck, wrists, or feet.
- Sleep with a damp sheet or wet socks to cool down at night.
Note: This method works best in low humidity areas. In humid regions, focus on shade and hydration instead.
Clay Pot Coolers
- Use the Zeer pot method: a smaller clay pot inside a larger one with wet sand in between. Cover with a damp cloth.
- Cools small items like water bottles or perishables without refrigeration.
Solar Chimneys
- Build a passive ventilation system using a black-painted vertical pipe to draw hot air out of your shelter. As the air heats, it rises, pulling cooler air from below.
4. Water is Your Lifeline
During a heatwave, you’ll need at least 1.5 to 2 times your normal water intake. For adults, that means at least 3 to 4 liters per day, more with physical exertion.
Ways to Stay Hydrated:
- Pre-mix oral rehydration salts or use store-bought electrolyte mixes.
- Store water in dark containers away from direct sunlight.
- Consider burying water containers underground to keep them cool.
- Treat and rotate stored water regularly to ensure safety.
5. Clothing & Body Cooling Strategies
Wear:
- Loose-fitting, light-colored, breathable fabrics (cotton, linen).
- Wide-brimmed hats or shemaghs to block sun.
- Cooling scarves or neck wraps soaked in water.
Avoid:
- Dark clothing
- Synthetic materials that trap heat
- Tight shoes or socks during the day
6. Create a Cool Sleeping Area
- Set up a sleeping area in the lowest part of your shelter—heat rises.
- Lay on a cot or raised bed to allow airflow underneath.
- Use a wet sheet or cloth over your body with a slight breeze if available.
- Sleep outdoors if safe, under mosquito netting.
7. Know the Signs of Heat-Related Illness
Watch for:
- Heavy sweating followed by no sweating
- Dizziness, nausea, confusion
- Rapid pulse, dry skin, headache
Treat Heat Illness Immediately:
- Move the person to shade
- Apply cool, wet cloths or submerge in water if possible
- Encourage small sips of water or rehydration fluids
- Avoid giving too much at once if vomiting is present
- Seek medical help if confusion or unconsciousness sets in
8. Long-Term Cooling Prepper Solutions
If you’re planning for future heat events, consider:
- Underground shelters or root cellars that stay cool
- Earthbag, cob, or adobe structures with thermal mass
- Solar-powered fans or swamp coolers with battery backup
- Rainwater harvesting for evaporative cooling and hydration
- Planting deciduous trees around your shelter for seasonal shade
Final Thoughts
Heatwaves are one of the deadliest weather events worldwide—and when the grid is down, your survival hinges on planning ahead. With a mix of shade, hydration, ventilation, and old-school cooling techniques, you can ride out extreme heat while keeping your group healthy and functional.
Stay alert, stay hydrated, and stay cool.
