I used to think my old apartment in Boston was the hottest place on earth some summer nights. Without air-conditioning, my roommate and I would sit motionless before our ‘poor man’s air conditioner’ – a towel soaked in cold water, wrung lightly, and hung in a wide-open window. We were hot and desperate enough to try anything. Hopefully, most homes and apartments today have air-conditioning units and are better prepared to deal with heat waves.

If you’re feeling the heat, here are a few preparations which can help reduce the impact of extreme heat waves.

1. Shield windows exposed to the sun.

Take note of the amount of direct sunlight your home receives at different times of the day, so you know which rooms contribute the most to heat build-up from direct sunlight. Shield the windows in those rooms accordingly. Even simply pulling down the shades will block sunlight and reduce indoor heat. If you’ll be away for the day, then shade the windows before you leave in the morning.

Awnings or louvers are ideal because they block sunlight without reducing air circulation around windows. Even temporary awnings can be installed using tarps or cardboard. It’s worth the effort, because the ‘awning effect’ can help reduce heat entering the house by as much as 80 percent.

Pulling down the shades or shutting the blinds will block sunlight and help keep indoor room temperatures down, but it can also reduce circulation in homes which do not have air conditioning. Leaving an air space between the shield and the window will help.

Reflectors can also be used to temporarily deflect sunlight from the windows. These are often used in cars to keep them cooler while in parking lots exposed to the sun; the same principle applies in the home. Identify the windows with greatest exposure to the sun and set reflectors in place. They can be removed in the evenings or after the heat wave passes.

2. Check for air leaks and clean a/c filter. Snug-up window units.

Homes with central air conditioning should be well sealed to keep cool air from escaping. Check the condition of weather-stripping around doors and windows, and seal any apparent air leaks. The air-conditioning filter should be clean, for best efficiency.

In rooms with window-mounted air conditioners, check to see the unit is snug to the window and there are no significant air leaks.

While you’re at it, set your thermostat at 78 degrees. If you set your thermostat below 78, you’ll add around 3% to 5% per degree to your cooling costs. Ceiling fans should also be used with the air conditioning. Ceiling fans cost about a penny an hour to run, and help offset the cost of using the air conditioning.

3. Refrigerate bottles of drinking water.

We become dehydrated more quickly in extreme heat, so we need to drink small amounts of water throughout the day. Bring a bottle of drinking water when leaving the home. Keep a few bottles of water chilling in the refrigerator. This helps save water because, when getting water at the tap, we tend to run the water to get it cooler before filling our glass.

4. Stock up on ‘cool’ foods.

Eating heavy meals will make you hotter, and cooking large meals adds heat to the house. During a heat wave, plan simpler meals that don’t require cooking. Salads and cold fruits like watermelon and cantaloupe are full of water and will help you stay cool. Sandwiches are easy to prepare from cold or room-temperature ingredients.

Some foods can be prepared in the evening or early morning when the temperature is cooler, then served cold during daytime meals. Deviled eggs, pasta salads and potato salads are filling and good served cold. It’s handy to have cooked chicken or fish in the refrigerator to add to salads for a more filling meal.

An ideal cooking method during hot weather is to use solar ovens. These ovens can be set outdoors on the patio or yard to provide ample cooking facilities for a family. This keeps heat associated with cooking out of the home.

If you need to cook indoors, use the microwave when possible to avoid heating up the kitchen.

5. Mulch your garden and shrub beds

Shrub beds, vegetable gardens and lawns are also stressed by extreme heat. The simplest way to protect your investment in shrubs is to add a thick layer of mulch around the base of the plant. If enough mulch is available, then it should be applied to the entire bed.

During a heat wave, mulch can be applied quickly, and it can be temporary if it does not meet with your landscaping aesthetics. After the heat wave, mulch can be easily removed and set in the compost. Mulch will reduce water loss from evaporation while shading the ground from direct sun. This keeps moisture in the soil close to the surface which protect roots and aids in soil aeration. Organic mulches also add soil humus as they break down.

The most commonly used mulch for residential shrub beds is bark mulch. Landscape cloth is usually set down before applying the mulch, since bark mulch does not break down quickly. Bark mulch is meant to be semi-permanent, and not intended to break down and incorporate into the soil. Bark mulch also has enough weight to it that it remains in place even in strong winds. When purchasing bark mulch, ask the clerk if there have complaints about weeds sprouting from the mulch. Bark mulches vary considerably in color, texture and potential weed seeds.

Straw is useful as a mulch and it has the advantage of breaking down more quickly than bark mulch for gardeners who value the soil-building properties of mulch. Landscaping cloth should not be used beneath straw mulch if you want to improve the soil. If you are buying straw for use as mulch, be sure that it is not hay, which if full of weed seeds.

Perhaps the easiest and readily available mulch is grass clippings. Grass clippings, like straw, will also benefit the soil as they break down, so don’t use landscape cloth beneath the clippings. The clippings will mat is layered too thickly, but this will eventually break down. Some gardeners mix leaves in with the grass clippings, but leaves are not always available in early summer.

To learn more about the types of mulch and their properties, see our Mulch Chart.

6. Know the Signs of Heat Stress

People most likely affected by the heat are the elderly, young children and those people with health problems. The following signs of heat stress can help alert you to take remedial action. Source: FEMA

Heat Cramps
Muscular pains and spasms due to heavy exertion. Although heat cramps are the least severe, they are often the first signal that the body is having trouble with the heat.

Heat Exhaustion
Typically occurs when people exercise heavily or work in a hot, humid place where body fluids are lost through heavy sweating. Blood flow to the skin increases, causing blood flow to decrease to the vital organs. This results in a form of mild shock. If not treated, the victim’s condition will worsen. Body temperature will keep rising and the victim may suffer heat stroke.

Heat Stroke
A life-threatening condition. The victim’s temperature control system, which produces sweating to cool the body, stops working. The body temperature can rise so high that brain damage and death may result if the body is not cooled quickly.

These suggestions are pretty easy to implement for quick short-term relief during a heat wave. But homeowners would be wise to plan for future heat waves by including elements in their landscaping, home design and cooling systems that will have long-term benefits. To learn more about passive strategies you can use in your home, see our page Natural Home Cooling.