What To Know When The Power Goes Out

If the power is out for less than 2 hours, then the food in your refrigerator and freezer will be safe to consume. While the power is out, keep the refrigerator and freezer doors closed as much as possible to keep food cold for longer.


  • For the freezer section: A freezer that is half full will hold food safely for up to 24 hours. A full freezer will hold food safely for 48 hours. Do not open the freezer door if you can avoid it.

  • For the refrigerated section: Pack milk, other dairy products, meat, fish, eggs, gravy, and spoilable leftovers into a cooler surrounded by ice. Inexpensive Styrofoam coolers are fine for this purpose.

  • Use a digital quick-response thermometer to check the temperature of your food right before you cook or eat it. Throw away any food that has a temperature of more than 40° Fahrenheit.


  • Always keep meat, poultry, fish, and eggs refrigerated at or below 40° F and frozen food at or below 0° F. This may be difficult when the power is out. Keep the refrigerator and freezer doors closed as much as possible to maintain the cold temperature. The refrigerator will keep food safely cold for about 4 hours if it is unopened. A full freezer will hold the temperature for approximately 48 hours (24 hours if it is half full) if the door remains closed. Obtain dry or block ice to keep your refrigerator as cold as possible if the power is going to be out for a prolonged period of time. Fifty pounds of dry ice should hold an 18-cubic foot full freezer for 2 days. Plan ahead and know where dry ice and block ice can be purchased.

  • Be prepared for an emergency by having items on hand that do not require refrigeration and can be eaten cold or heated on the outdoor grill. Shelf-stable food, boxed or canned milk, water, and canned goods should be part of a planned emergency food supply. Make sure you have ready-to-use baby formula for infants and pet food. Remember to use these items and replace them from time to time. Be sure to keep a hand-held can opener for an emergency.

  • Consider what you can do ahead of time to store your food safely in an emergency. If you live in a location that could be affected by a flood, plan your food storage on shelves that will be safely out of the way of contaminated water. Coolers are a great help for keeping food cold if the power will be out for more than 4 hours - have a couple on hand along with frozen gel packs. When your freezer is not full, keep items close together - this helps the food stay cold longer.

  • Digital, dial, or instant-read food thermometers and appliance thermometers will help you know if the food is at safe temperatures. Keep appliance thermometers in the refrigerator and freezer at all times. When the power is out, an appliance thermometer will always indicate the temperature in the refrigerator and freezer no matter how long the power has been out. The refrigerator temperature should be 40 ° F or below; the freezer, 0° F or lower. If you're not sure a particular food is cold enough, take its temperature with a food thermometer.


When power goes out, water purification systems may not be functioning fully. Use bottled water for eating or drinking. If you do not have bottled water on hand, and are not sure that your tap water is safe, follow these directions to purify tap water:

  • Boil the water vigorously (water should be bubbling and rolling) for 1 minute.

  • If you cannot boil water, add 6 drops of newly purchased liquid household bleach per gallon of water, stir it well, and then let the water stand for 30 minutes before you use it.

  • You also can use water-purifying tablets from your local pharmacy.


  • Be aware of yours and others' risk for heat stroke, heat exhaustion, heat cramps and fainting. To avoid heat stress, you should:

  • Drink a glass of fluid every 15 to 20 minutes and at least one gallon each day.

  • Avoid alcohol and caffeine. They both dehydrate the body.

  • Wear light-colored, loose-fitting clothing.

  • When indoors without air conditioning, open windows if outdoor air quality permits and use fans.

  • Take frequent cool showers or baths.

  • If you feel dizzy, weak, or overheated, go to a cool place. Sit or lie down, drink water, and wash your face with cool water. If you do not feel better soon, get medical help quickly.

  • Work during cooler hours of the day when possible, or distribute the workload evenly throughout the day.

  • Heat stroke is the most serious heat illness. It happens when the body cannot control its own temperature and its temperature rises rapidly. Sweating fails and the body cannot cool down. Body temperature may rise to 106°F or higher within 10 to 15 minutes. Heat stroke can cause death or permanent disability if emergency care is not given.

  • Warning signs of heat stroke vary but can include:

  • Red, hot, and dry skin (no sweating)

  • Rapid, strong pulse

  • Throbbing headache

  • Dizziness, nausea, confusion, or unconsciousness

  • An extremely high body temperature (above 103°F)

  • If you suspect someone has heat stroke, follow these instructions:

  • Immediately call for medical attention.

  • Get the person to a cooler area.

  • Cool the person rapidly by immersing him/her cool water or a cool shower, or spraying or sponging him/her with cool water. If the humidity is low, wrap the person in a cool, wet sheet and fan him/her vigorously.

  • Monitor body temperature and continue cooling efforts until the body temperature drops to 101-102°F.

  • Do not give the person alcohol to drink. Get medical assistance as soon as possible.

  • If emergency medical personnel do not arrive quickly, call the hospital emergency room for further instructions.


  • Hypothermia happens when a person's core body temperature is lower than 35°C (95°F). Hypothermia has three levels: acute, subacute, or chronic.

  • Acute hypothermia is caused by a rapid loss of body heat, usually from immersion in cold water.

  • Subacute hypothermia often happens in cool outdoor weather (below 10°C or 50°F) when wind chill, wet or too little clothing, fatigue, and/or poor nutrition lower the body's ability to cope with cold.

  • Chronic hypothermia happens from ongoing exposure to cold indoor temperatures (below 16°C or 60°F). The poor, the elderly, people who have hypothyroidism, people who take sedative-hypnotics, and drug and alcohol abusers are prone to chronic hypothermia, and they typically:

  • Misjudge cold.

  • Move slowly.

  • Have poor nutrition.

  • Wear too little clothing.

  • Have a poor heating system.


  • Cold temperatures.

  • Improper clothing, shelter, or heatin.

  • Wetness.

  • Fatigue, exhaustion.

  • Poor fluid intake (dehydration).

  • Poor food intake.

  • Alcohol intake.


  • Everyone, especially the elderly and ill, should have adequate food, clothing, shelter, and sources of heat.

  • Electric blankets can help, even in poorly heated rooms.

  • Wear layers of clothing which help to keep in body heat.

  • Move around. Physical activity raises body temperature.

  • Water cooler than 75° F (24° C) removes body heat more rapidly than can be replaced. The result is hypothermia. To avoid hypothermia:

  • Avoid swimming or wading in water if possible.

  • If entering water is necessary:

  • Wear high rubber boots in water.

  • Ensure clothing and boots have adequate insulation.

  • Avoid working/playing alone.

  • Take frequent breaks out of the water.

  • Change into dry clothing when possible.


  • As the body temperature decreases, the person will be less awake and aware and may be confused and dazed. Because of this, even a mildly hypothermic person might not think to help himself/herself.

  • Even someone who shows no signs of life should be brought quickly and carefully to a hospital or other medical facility.

  • Do not rub or massage the skin.

  • People who have severe hypothermia must be carefully rewarmed and their temperatures must be monitored.

  • Do not use direct heat or hot water to warm the person.

  • Give the person warm beverages to drink.

  • Do not give the person alcohol or cigarettes. Blood flow needs to be improved, and these slow blood flow.


  • If you believe someone has been electrocuted take the following steps:

  • Look first. Do not touch. The person may still be in contact with the electrical source. Touching the person may pass the current through you.

  • Call or have someone else call 911 or emergency medical help.

  • Turn off the source of electricity if possible. If not, move the source away from you and the affected person using a nonconducting object made of cardboard, plastic or wood.

  • Once the person is free of the source of electricity, check the person's breathing and pulse. If either has stopped or seems dangerously slow or shallow, begin cardiopulmonary resuscitation (CPR) immediately.

  • If the person is faint or pale or shows other signs of shock, lay the person down with the head slightly lower than the trunk of his or her body and the legs elevated.

  • Do not touch burns, break blisters, or remove burned clothing. Electrical shock may cause burns inside the body, so be sure the person is taken to a caregiver.


  • If a power line falls on a car, you should stay inside the vehicle. This is the safest place to stay. Warn people not to touch the car or the line. Call or ask someone to call the local utility company and emergency services.

  • The only circumstance in which you should consider leaving a car that is in contact with a downed power line is if the vehicle catches on fire. Open the door; do not step out of the car as you may receive a shock. Instead, jump free of the car so that your body clears the vehicle before touching the ground. Once you clear the car, shuffle at least 50 feet away, with both feet on the ground.

  • As in all power line related emergencies, call for help immediately by dialing 911 or call your electric utility company's Service Center/Dispatch Office.

  • Do not try to help someone else from the car while you are standing on the ground.


As power returns after an outage, people at work may be at risk of electrical or traumatic injuries as power lines are reenergized and equipment is reactivated. CDC recommends that employers and employees be aware of those risks and take protective steps if they are in contact with or in proximity to power lines, electrical components, and the moving parts of heavy machinery.


CDC recommends that people make an emergency plan that includes a disaster supply kit. This kit should include enough water, dried and canned food, and emergency supplies (flashlights, batteries, first-aid supplies, prescription medicines, and a digital thermometer) to last at least 3 days. Use battery-powered flashlights and lanterns, rather than candles, gas lanterns, or torches (to minimize the risk of fire).

Information courtesy of the CDC.