Hurricane Irma is threatening Florida at the same time that residents of Houston and the Gulf Coast are working to recover from Harvey. We're reminded that surviving a storm is about more than simply making it through the worst of the weather. It can also require making a plan to live for days or weeks with closed roads, long gas lines, and widespread power outages.

(Here are some ways to help those affected by Hurricane Harvey.)

As utility crews work to get the lights back on, a generator is an invaluable piece of equipment that can help your life start to feel normal again.

But since you probably rarely rely on a generator, it’s easy to overlook the sort of basic safety measures that should be routine with such equipment. It’s also easy to get preoccupied by the cleanup work that lies ahead, so you may even be tempted to run a generator in a living space if most of your house is severely water damaged and cannot be saved. That is never an option.

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Generator misuse leads to carbon monoxide deaths, injuries from close calls, and burns—all of which happen too often during power outages and storms.

“Portable generators can produce high levels of carbon monoxide, a deadly, odorless, and colorless gas,” says Ann Marie Buerkle, acting chair of the Consumer Product Safety Commission.

Running a generator improperly can kill you in as little as 5 minutes if the concentration of carbon monoxide is high enough. The CPSC estimates that about 50 people die per year from carbon monoxide poisoning related to using a generator improperly. We want you to be safe.

Here are CR’s essential generator safety tips to get you through a storm and the days afterward.

Never run a generator in an enclosed space or indoors. Most generator-related injuries and deaths involve CO poisoning from generators used indoors or in partially enclosed spaces. That includes the basement or garage, spaces that can capture deadly levels of carbon monoxide. Always place the generator at least 15 feet from the house and away from doors and windows.

And if you’re using a generator to keep the lights on during a cleanup effort, “use a working, battery-operated carbon monoxide detector at the same time,” says Ken Boyce, principal designated engineer manager at UL. A carbon monoxide alarm provides one more layer of defense against making an innocent but potentially deadly mistake.

Don’t run a portable generator in the rain. The exception is if you cover and vent it. You can buy model-specific tents online and generic covers at home centers and hardware stores.

Before refueling, turn off a gasoline-powered generator and let it cool. Gasoline spilled on hot engine parts can ignite. Allowing the engine to cool also reduces the risks of burns while refueling.

Stock up on extra gasoline and store it properly. When you think you’ll need to use the generator for an extended time, you’ll want extra fuel on hand. Just be sure to store gas only in an ANSI-approved container in a cool, well-ventilated place.

Adding stabilizer to the gas in the can will help it last longer, but don’t store gasoline near any potential sources of heat or fire, or inside the house.

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Avoid electrical hazards. If you don’t yet have a transfer switch, you can use the outlets on the generator if you follow certain precautions. It’s best to plug in appliances directly to the generator. If you must use an extension cord, it should be a heavy-duty one for outdoor use, rated (in watts or amps) at least equal to the sum of the connected appliance loads. First check that the entire cord is free of cuts and that the plug has all three prongs, critical to protect against a shock if water has collected inside the equipment.

Install a transfer switch before the next storm. This critical connection will cost from $500 to $900 with labor for a 5,000-rated-watt or larger generator. A transfer switch connects the generator to your circuit panel and lets you power hardwired appliances while avoiding the glaring safety risk of using extension cords. Most transfer switches also help you avoid overload by displaying wattage usage levels.

Don’t attempt to backfeed your house. Backfeeding means trying to power your home’s wiring by plugging the generator into a wall outlet. This reckless and dangerous practice presents an electrocution risk to utility workers and neighbors served by the same utility transformer. It also bypasses some of the built-in household circuit protection devices, so you could end up frying some of your electronics or starting an electrical fire.

Editor’s Note: A version of this article also appeared in the October 2016 issue of Consumer Reports magazine.