RICHMOND, Va. (WRIC) — As the cold finally settles in, Virginians are preparing for winter power outages. One common way to get electricity during an outage is with a portable generator, but the tool can have hidden dangers.

Portable generators are a common way to keep your family warm and to power household staples like your fridge and your lights. But using a generator incorrectly can cause injury. Generators have previously been taken off the market for crushing and even amputating people’s fingers.

Even if you use a generator safely and with no injury, another more invisible threat lurks. Generators can produce a high amount of carbon monoxide, which can lead to fainting and even death, according to the Center for Disease Control.

To prevent being harmed by emissions, install a carbon monoxide detector in your home before using a generator. If dangerous levels make it inside, the alarm will sound and you and your family will be able to leave before you are harmed.

If you cannot install a generator, be wary of side effects of carbon monoxide poisoning, which can include flu-like symptoms like headache, dizziness, weakness, upset stomach, vomiting, chest pain, and confusion, according to the Center for Disease Control.