How to Stay Cool in a Heatwave Even If the Power Goes Out

By Jennifer Youngren, NDTR

When the power goes out and the heat climbs to triple digits, how do you keep your body safe, your kids hydrated, and your sanity intact? As climate extremes become the new normal, we need more than just air conditioning. We need strategy, preparation, and a solid understanding of how the human body responds to heat stress.

This article offers practical, research-backed methods to help you stay cool, nourished, and safe—even on the hottest days—without depending on power-hungry cooling systems.

Understanding Heat Stress and the Body’s Response

The human body is designed to regulate internal temperature through a process known as thermoregulation. When the core body temperature rises above normal (about 98.6°F), the body initiates cooling through mechanisms like sweating and increased blood flow to the skin. However, in high heat and humidity, especially during prolonged exposure or physical activity, these mechanisms can become overwhelmed.

According to the Centers for Disease Control and Prevention (CDC), heat-related illness can range from heat cramps to life-threatening heat stroke. Symptoms often include heavy sweating, dizziness, fatigue, and nausea. Once the body is no longer able to cool itself effectively, internal organs may begin to overheat, making prevention not only essential but potentially life-saving.

Evaporative Cooling: A Scientific Approach

Evaporative cooling is one of the most efficient methods of lowering body temperature when air conditioning isn’t available. A 2019 study published in the Journal of the American Medical Association (JAMA) found that skin-wetting interventions—such as spraying the skin with water and using a fan—were significantly more effective at reducing cardiovascular strain than drinking water alone in extreme heat conditions.

To take advantage of this, try:

• Damping a cloth or t-shirt and applying it to the neck, wrists, and ankles

  
  

• Using a spray bottle to intermittently mist your skin

  
  

• Soaking your feet in a tub of cool water or relaxing in a shallow kiddie pool

  
  

• Placing a bowl of ice or a frozen water jug in front of a battery-powered fan to enhance cooling through airflow

These techniques rely on evaporation, which draws heat away from the body as water turns to vapor. Even without electricity, this can offer noticeable relief.

Block Heat Intelligently

1. Keep blinds and curtains drawn during the day, especially on sun-facing windows. Blackout curtains can reduce heat gain by up to 33 percent

   
   

2. Open windows strategically at night or early morning to create cross-ventilation if the outdoor temperature is lower than inside

   
   

3. Unplug heat-producing devices like televisions, ovens, and lights. Even small electronics can warm your space

   
   

4. Use lightweight, breathable fabrics indoors and, if possible, move to the lowest level of your home where it tends to stay cooler.

   
   

Passive Cooling and Environmental Control

Creating a cool indoor environment without air conditioning requires thoughtful planning. Passive cooling strategies include using shade, insulation, and airflow to minimize indoor heat buildup. The U.S. Department of Energy recommends blocking direct sunlight with heavy curtains or blackout shades, particularly on south- and west-facing windows. Reflective shades or aluminum foil can also be used to redirect sunlight.

Cross-ventilation is another highly effective method. Opening windows at night or in the early morning—when outdoor temperatures are lower—can flush out trapped heat. During peak daylight hours, windows should remain closed to prevent hot air from entering.

Also, avoid using heat-producing appliances like ovens and stovetops. Consider cooking outdoors or preparing no-cook meals to keep indoor temperatures down.

Hydration as a Daily Practice

Staying hydrated is essential for maintaining circulation, supporting sweat production, and preventing heat-induced fatigue. According to the National Academies of Sciences, Engineering, and Medicine, the average daily fluid intake should be approximately 2.7 liters (91 ounces) for women and 3.7 liters (125 ounces) for men. However, these needs increase with physical activity, high temperatures, and humidity.

Instead of guzzling large amounts of water infrequently, sip steadily throughout the day. Electrolyte loss is another critical factor. When we sweat, we lose sodium, potassium, and magnesium—all of which play roles in muscle function and hydration regulation.

Here are ways to support hydration:

• Eat foods rich in water and electrolytes (see next section)

  
  

• Add a pinch of salt to water or fruit slices to aid in fluid retention

  
  

• Use low-sugar electrolyte beverages when experiencing heavy sweating or dizziness

  
  

• Avoid sugary drinks and excess caffeine or alcohol, which can promote fluid loss

Hydrating Foods That Do More Than Quench Thirst

Food can be a powerful tool in managing heat. High-water-content fruits and vegetables provide both hydration and nutrients that support thermoregulation. A 2023 review in the journal Nutrients emphasizes the role of food-derived fluid intake in maintaining electrolyte balance and reducing oxidative stress during heat exposure.

Here are some of the most hydrating foods:

Watermelon (92%)

Cucumber (96%)

Strawberries (91%)

Zucchini (94%)

Tomatoes (94%)

Celery (95%)

In addition to hydration, these foods supply antioxidants like lycopene (in tomatoes) and vitamin C (in strawberries), which may help mitigate cellular damage from heat-related stress.

Easy hydrating meals include:

• Classic gazpacho made with tomatoes, cucumbers, and bell peppers

• Chilled watermelon mint salad with sea salt

• Plain Greek yogurt topped with fresh berries and chia seeds

• Frozen fruit added to sparkling water for a refreshing, mineral-rich drink

A Surprising Sip: Can Hot Coffee Cool You Down?

It might seem counterintuitive, but drinking hot beverages like coffee can actually help cool the body under certain conditions. The theory, supported by research from the University of Ottawa’s School of Human Kinetics, is that consuming a hot drink increases your body temperature slightly, which triggers a greater sweat response. As that sweat evaporates, it cools you down—provided it can evaporate efficiently (i.e., in dry climates or when wearing breathable clothing).

I’ve seen this in real life: my aunt and uncle used to sit outside on sweltering summer days sipping hot coffee. I always thought they were a little wild for doing it, but they insisted it helped their bodies “cool from the inside out.” Now, it turns out they were onto something. Just remember, this only works when the sweat can evaporate properly—so if it’s humid or you’re not able to sweat freely, a cold drink may still be your better bet.

Emergency Cooling Kit (No AC Required)

Preparing for a heatwave or power outage doesn’t have to be complicated. Stocking a few essential items can make all the difference:

• Battery-operated fan

• Refillable spray bottle

• Rice-filled sock or gel packs to freeze and use in bedding

• Large water containers or frozen jugs for passive cooling

• Salted snacks and low-sugar electrolyte drinks

• Pre-sliced fruit and cold vegetables, ready to grab

If your home has shaded outdoor space, use it to your advantage. A simple kiddie pool or water basin becomes a relief station when the temperatures rise.

Recognizing Heat Stress Before It Escalates

Understanding the early signs of heat-related illness can help prevent more serious complications. Symptoms like headache, nausea, rapid heart rate, muscle cramps, and confusion should never be ignored. Heat stroke can occur when body temperature rises above 104°F and should be treated as a medical emergency.

Immediate first aid includes moving the person to a shaded or air-cooled area, applying wet cloths to the skin, and encouraging frequent sips of water while waiting for emergency care.

Heat exhaustion can progress quickly into heat stroke, which is life-threatening. By combining cooling techniques with steady hydration, you reduce this risk significantly.

The Takeaway: Resilience Begins with Knowledge

Staying safe in extreme heat doesn’t always require access to central air or fancy gadgets. With preparation, awareness, and a few practical tools, you can protect yourself and your family from the serious risks of heat exposure.

Eat smart. Hydrate intentionally. Trust your body’s cues.

Staying safe in extreme heat doesn’t require high-tech tools or constant electricity. With a few essential supplies, intentional eating, and time-tested cooling practices, your body can adapt and recover—day after day.

For personalized nutrition or hydration support, reach out.