Extension cords are convenient, but we often use them incorrectly. Instead of serving as a temporary solution, in many homes they have become a permanent power source for everything from chargers to heaters. And that's where the problem comes in: not all devices are safe when plugged into an extension cord. Some can cause overheating, short circuits, or even fires.
Heaters and calorifiers
This is the most common and dangerous mistake. Heaters use a lot of electricity and generate heat that can quickly overheat the cable. If the cable gets too hot, the insulation can melt, and a spark is enough to start a fire. Heaters should always be plugged directly into a wall outlet.
Air conditioners and oil heaters
Similar to heaters, these devices have a high electricity consumption. An extension cord often cannot withstand such a load, especially if other appliances are already connected to the same cord.
Refrigerators and freezers
These devices operate continuously, and when the compressor starts working, there is a short but strong spike in consumption. An extension cord does not handle this well, and prolonged use can cause damage to the motor or electrical installation.
Washing machines and dishwashers
Machines constantly change power during operation – especially when heating water. This means voltage fluctuations that an extension cord cannot safely “dampen”. Plugging a machine into an extension cord increases the risk of overheating, especially in damp rooms such as bathrooms.
Microwave and toaster
Although they may seem harmless, these small appliances draw a lot of current when they are in use. A microwave can easily blow a fuse if it shares a cord with other appliances. It is best to leave it plugged into a separate outlet.
Iron
The iron combines heat and high consumption. When plugged into an extension cord, especially a poor quality one, there is a risk of overheating the connections, especially if the cord is not fully unwound.
Hair dryer and straightener
It sounds practical in the bathroom, but these are devices that consume more electricity than we think. They are short-lived, but very intensive consumers. If the cable heats up, combined with moisture, it can become dangerous.
Laptop and phone chargers – but with a fence
Chargers themselves don't use much power, but the problem arises when multiple chargers are connected to a single extension cord, along with other devices. This puts a strain on the system and can damage both the charger and the device.
How to know when it's time to replace your extension cord
If you smell plastic, the cord gets hot, the outlets are loose, or appliances frequently “turn off by themselves,” it’s a clear sign that the cord is worn out. An extension cord isn’t designed to last for years — especially if it’s constantly under stress.
Quick rule: An extension cord is for a lamp, charger, or TV – but not for appliances that heat, cool, wash, or cook.
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