If you plan on snagging a new air fryer or space heater this holiday season, make sure you consider where you're going to plug everything in. If you're like me, you may have one kitchen outlet and a slew of items you need to plug in. Logic might tell you to add everything to your extension cord and keep it moving, but experts say otherwise. In fact, when it comes to certain high-powered devices that's something you should try to avoid.

"A lot of people don't have knowledge of extension cords," said Paul Martinez, owner of Electrified NYC, in Brooklyn, New York. "If extension cords are 14-gauge, and you're running an appliance with a heating element, [such as] a toaster oven, microwave or dishwasher, a 14-gauge will not hold the amperage and can burn up the extension cord. And that's what causes fires in New York City."

Fourteen- and 12-gauge extension cords are some of the most common extension cords sold with a 14-gauge extension cord being able to handle roughly up to 1,800 watts (or 15 amps, which is the same as a standard wall outlet in the US).

However, Martinez warns that any appliance of more than 1,500 watts should always be on a dedicated circuit. "No extension cords whatsoever," he says for such appliances.

Here are seven high-risk examples in your home that you should never connect to an extension cord.

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1. Air fryer

Air fryers are great for quickly cooking and warming food, including full meals and side dishes, but it's not a good idea to attach them to an extension cord or power strip. Although they range in wattage based on size, large air fryers can draw up to 2,000 watts, making them a major fire hazard if they're attached to an extension cord. So if you don't have counter space to keep your air fryer out full time, it's best to pull it out when needed and plug it into a dedicated wall outlet.

2. Microwave

While the dream is to move into a home with a built-in microwave, we're all not that lucky. If you have to find a place to connect yours in your kitchen, this is another heavy-duty appliance that should live on its own dedicated circuit due to high wattage.

Read more: Best Microwave for 2024

3. Extension cords

Plugging extension cords into other extension cords is another huge "no!" in the electrician world. When this is done, it's known as "daisy chaining." It can lead to the circuit overheating, which would cause the cords to overheat.

4. Toaster and toaster oven

Although toasters are on the smaller side when it comes to kitchen appliances, they use a lot of energy and pose a fire threat if connected to an extension cord. Toaster ovens need even more power to operate with wattage ranging from 1,200 to 1,400 watts.

5.  Refrigerator

Although refrigerators use less wattage than some other kitchen appliances, they're still not recommended for extension cord use as they are constantly running. Even if the extension cord doesn't cause a fire when attached to a fridge, there's a possibility it could cause the fridge to malfunction.

6. Space heaters

Electric heaters have long been known to be a major cause of fires. The Consumer Product Safety Commission previously estimated that between 2017 and 2019, portable space heaters were involved in 1,700 fires per year, with some of those fires resulting in deaths.

"Let's say you connect [an extension cord] to a floor heater," Martinez says, "the plug melts and it starts a fire. That's why you can't use extension cords and/or power strips for any appliances, because they should be used for electronics only."

Read more: Never Put a Space Heater in These 9 Places

7. AC unit

AC units use too much power for an extension cord or power strip, so they need to be attached to a wall outlet as well. Martinez also stresses the importance of purchasing the correct AC unit for your space. You can use an online BTU calculator to calculate the type you will need to effectively cool your space.

"People just buy a 5,000 BTU air conditioner, because it's $99 on sale, and they think it's going to cool off [their home], and it does not, " Martinez says. "[AC units] are supposed to cycle on and off, so they don't pull that much energy. So if you undersize it, the compressor is going to work 10 times harder."

This can result in your home never properly cooling off, a higher electricity bill, and if this AC unit is connected to an extension cord, possibly a fire.

The bottom line when it comes to extension cords

"No appliances whatsoever," Martinez says, regarding extension cords and power strips.

He says you should also remember to only pair power strips with electronics, and that extension cords shouldn't be used for anything above 15 amps (1,800 watts), regardless of where or how the item operates.

For more home tips, see how much you can save using a space heater and learn where you should never put a home security camera.