Heatwave Preparation

Although tornadoes, hurricanes, and earthquakes cause more property damage, fatalities, and illnesses due to a heat wave can far outnumber other natural disasters. In the US alone, heat was the deadliest of all weather-related fatalities not across a thirty-year span, and is currently tied with floods, tornados for the most fatalities across a ten-year span.

As the rising temperatures of summer are upon us, it’s never too soon to prepare your properties and tenants for the next heat wave. 

Heat Index = Temperature Plus Humidity

Like the wind-chill factor in winter, a heat index is based on how hot it feels. This sounds subjective as we all feel differently about temperature fluctuations, however, it is a more objective scientific calculation that takes into account not only temperature but also relative humidity. 

Pay attention to the rising summer temperatures but when humidity rises over forty percent it’s time to be alert and vigilant. Check out this NWS Heat Index Graph showing the likelihood of heat disorders with prolonged exposure or strenuous activity ranging from caution to extreme danger. 

Even in areas commonly over one hundred degrees in summer a slight increase of humidity can quickly change a warm day into one of extreme concern. 

Factors That Increase Heat Wave Danger

If high temperatures and a rising heat index weren’t enough, other factors may intensify the dangers of basic high temperatures and extreme heat during a heat wave.


  • Warm wind can potentially lead to dehydration.
  • A high-pressure system can create a heat dome that can lock in and intensify hot air.
  • Off or early-season heat can catch people off-guard and unprepared.
  • Extended days of heat (especially without relief at night) build momentum that compound consequences.
  • Lack of vegetation or cloud cover increases building and pavement temperatures.

Age and Health

The elderly, children, and/or those with compromised health concerns are especially vulnerable during a heat wave. 

Power Outages 

Power outages are common in a heat wave as the demand on the power grid is often too great to accommodate the need to maintain cooler indoor temperatures. 

Work and Home Environment 

Those who participate in outdoor activities or occupations, or live or work in buildings without adequate cooling and/or ventilation are at a greater risk. 

Types of Heat Warnings

The National Oceanic and Atmospheric Administration (NOAA) maintains the National Weather Service (NWS) and outlines the three levels of public service heat wave alerts. Each State and County determine the criteria for what is considered an elevated heat index. From those criteria, heat warnings are issued.  

Heat Advisory

A heat advisory notice is given when the heat index remains at or above that local criteria for over two hours. At this level, people and animals can be affected if no precautions are taken. 

Excessive Heat Warning

An excessive heat warning is when the heat index is at or above 105 degrees Fahrenheit for longer than two hours. At this level, people and animals can be severely affected and mortality rates increase if no precautions are taken. 

Excessive Heat Watches

Sometimes heat waves come on without warning but when a heat warning is possible and foreseeable a watch notice will be issued. This one to two-day advance notice is useful to being prepared for worsening conditions. 

Prepare Your Rental Properties For a Heat Wave

Internal Preparation

Some states require a landlord to provide air conditioning as part of providing a safe and habitable rental. Some state regulations do not mandate providing a cooling system but may require a landlord to keep any provided in good working order. Make sure you know your local and state laws regarding a tenant’s right to air conditioning to maintain compliance. 

Move-in, move-out, and yearly rental inspections are a good time to check up on any air-conditioning maintenance. If within the lease or rental agreement, your tenants should be replacing (or cleaning if appropriate) any air-filters. If this responsibility falls on you, either add the task to the yearly rental inspection visit or hire a vendor to inspect and maintain all of your heating and air systems. 

Because darker colors absorb the energy of the sun, use only darker hues for accent walls where they are not in direct exposure to sunlight and use white or light-colored paint for all other walls.

Remember to choose energy-efficient appliances and window treatments when possible. 

External Preparation

The Department of Energy, in this comprehensive guide, “Cooling Your Home Naturally” states the most effective method to cool a home is to keep the heat from building up in the first place. They recommend a homeowner:

  • Use light-colored and/or heat-reflective exterior paint
  • Add reflective coating on roofs and windows
  • Provide additional insulation and other weatherization measures
  • Install external window shades and awnings
  • Develop landscaping features and plants to provide shade

In addition to the above detailed with strategies and tips, the guide offers a Cooling Strategies Checklist, Source List, and additional Reading List for your consideration. 

Heat Wave Safety Tips for Your Tenants

Your tenants are ultimately responsible for their health and well-being. However, a tenant will likely appreciate a property manager or landlord that offers helpful suggestions. Consider sending out email reminders or adding information in a tenant welcome basket with suggestions on topics such as:

  • What to stock in a first aid and/or emergency supply kit
  • What to include in a family emergency plan
  • How to maintain or change out air-filters in air conditioners
  • How to submit work-order requests using your property management software
  • What the signs and treatments for heat-related illnesses are such as heat exhaustion, heatstroke, sunburns, and heat cramps
  • How to be prepared for a power outage (as they are often common in extreme heat).

Heat Wave Tips for Landlords and Tenants 

Stay Cool

  • Use cotton or linen sheets on your bed. Placing damp sheets in the freezer and using them before bed may help keep you cool at night.
  • Consider removing a memory foam topper if it retains heat.
  • Freeze damp towels and rags and cycle them back to the freezer when thawed.
  • Go to cooler public spaces such as malls, libraries, or shelters, especially if you do not have air-conditioning available.
  • Take lukewarm to cool baths, sponge baths or showers.
  • Use ice on wrists and other pulse points to reduce body temperature.
  • Wear clothing made from breathable material such as linen or cotton.
  • Do not use the stove or oven to cook and eat small meals more often.
  • Unplug unused electronic equipment and devices.
  • Limit turning on unnecessary lights or electronics.
  • Chose to do chores or other activities later in the evening when it is coolest.
  • If the temperature drops at night below your home’s indoor temperature, open your windows. Be sure to close early in the morning before the heat increases.

Stay Indoors

  • Avoid going outdoors, especially between the hours of 10 am to 4 pm.
  • If going outdoors is unavoidable, wear a brimmed hat or use an umbrella.

Stay Healthy

  • Watch for signs and seek medical attention if someone is experiencing symptoms of a heat-related illness.
  • Keep hydrated.
  • Never stay in the car, nor leave anyone, including your pets in a car.
  • Avoid strenuous activities.

Heat Wave Resources

Keeping up with the best information and preparing for any disaster your rental properties and tenants might encounter could be a life-saver. Staying well informed and ready is key. Here are some resources from the experts to help you and your tenants keep your cool whatever the forecast. 

The American Red Cross: Heat Wave Safety

Department of Homeland Security: Plan Ahead for Disasters  

Federal Emergency Management Agency (FEMA): Preparing for Extreme Heat 

The National Weather Service: Heat Safety Tips and Resources

This article was originally published on July 2022 and has since been updated.