10 Things You Should Never Plug Into An Extension Cord
The Hidden Dangers of Extension Cords: What Not to Plug In
Space heaters
Refrigerators and freezers
Microwaves
Air conditioners
Washing machines
Hair dryers and styling tools
Power tools
Treadmills and exercise equipment
Coffee makers and electric kettles
Other extension cords or power strips
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Extension cords are everywhere—behind couches, under desks, and in almost every home. They’re convenient, cheap, and seem harmless. But using them the wrong way can be extremely dangerous. Many house fires, electrical failures, and appliance damages happen simply because something was plugged into an extension cord when it never should have been.
Understanding what not to plug into an extension cord is just as important as knowing how to use one properly. Below are ten common items that should never be connected to an extension cord—and the real reasons why.
1. Space Heaters
Space heaters consume a massive amount of electricity in a short time. They are one of the most dangerous appliances to plug into an extension cord.
Why It’s Dangerous:
Extension cords are not designed to handle the high wattage that space heaters draw, which can cause overheating.
What Can Go Wrong:
The cord can melt, spark, or ignite nearby materials, leading to serious house fires.
What to Do Instead:
Plug space heaters directly into a wall outlet and keep them away from flammable objects.
2. Refrigerators and Freezers
Large appliances like refrigerators require a steady and powerful electrical current.
Why It’s Dangerous:
Extension cords can’t provide consistent power, which stresses both the cord and the appliance.
What Can Go Wrong:
Power fluctuations can damage the compressor, shorten the appliance’s lifespan, or cause overheating.
What to Do Instead:
Always plug refrigerators directly into a dedicated wall outlet.
3. Microwaves
Microwaves may seem harmless, but they pull a large surge of electricity when operating.
Why It’s Dangerous:
Most extension cords are not rated to handle the sudden power demand.
What Can Go Wrong:
Overheating, electrical shorts, or even sparks inside the cord.
What to Do Instead:
Use a wall outlet with proper grounding and avoid power strips entirely.
4. Air Conditioners
Portable and window air conditioners are among the highest power-consuming home devices.
Why It’s Dangerous:
They draw continuous high current, which extension cords can’t safely support.
What Can Go Wrong:
Cord overheating, circuit overload, and increased fire risk.
What to Do Instead:
Plug air conditioners directly into a wall outlet designed for high-load appliances.
5. Washing Machines
Washing machines require strong electrical flow, especially during spin cycles.
Why It’s Dangerous:
Extension cords aren’t built for vibration, moisture, and heavy electrical demand at the same time.
What Can Go Wrong:
Electrical shocks, cord damage, or short circuits in damp environments.
What to Do Instead:
Always use a grounded wall outlet near the appliance.
6. Dryers and Hair Styling Tools
Hair dryers, curling irons, and straighteners draw high wattage—even though they’re small.
Why It’s Dangerous:
They heat up quickly and pull more power than most people realize.
What Can Go Wrong:
Cord overheating, melted insulation, and potential burns or fires.
What to Do Instead:
Plug directly into a wall outlet and unplug immediately after use.
7. Power Tools
Drills, saws, and other power tools can cause sudden electrical surges.
Why It’s Dangerous:
Extension cords may not handle the startup surge or sustained load.
What Can Go Wrong:
Tool malfunction, damaged motors, or electrical fires.
What to Do Instead:
Use heavy-duty, outdoor-rated cords only if absolutely necessary—and never indoors for long periods.
8. Treadmills and Exercise Equipment
Fitness machines often include motors, screens, and sensors that need stable power.
Why It’s Dangerous:
Extension cords can’t deliver consistent voltage for motor-driven equipment.
What Can Go Wrong:
Sudden shutdowns, damaged electronics, or overheating.
What to Do Instead:
Plug directly into a wall outlet with proper grounding.
9. Coffee Makers and Electric Kettles
Anything that heats water uses a significant amount of electricity.
Why It’s Dangerous:
Heating elements draw intense power instantly.
What Can Go Wrong:
Cord overheating, tripped breakers, or internal appliance damage.
What to Do Instead:
Use wall outlets only, especially for daily-use kitchen appliances.
10. Another Extension Cord or Power Strip
Daisy-chaining cords is one of the most common—and dangerous—mistakes.
Why It’s Dangerous:
Each additional connection increases resistance and heat.
What Can Go Wrong:
Overloaded circuits, melted plugs, and high fire risk.
What to Do Instead:
Use one properly rated cord only, or install more wall outlets if needed.
Conclusion
Extension cords are meant for temporary, low-power use—not as permanent solutions for heavy appliances. Plugging the wrong device into an extension cord can lead to damaged electronics, electrical shocks, or devastating fires. Most of these dangers are completely preventable with basic awareness and safe habits.
If an appliance generates heat, uses a motor, or runs continuously, it almost always belongs directly in a wall outlet. When in doubt, safety should always come first.