Millions of Floridians are still without power after Hurricane Irma, and many residents have been using portable generators for days. But those generators - if improperly used - can result in potentially deadly carbon monoxide (CO) poisoning.

There have been reports of at least 74 cases of CO poisoning over the last two days, prompting a warning from the Florida College of Emergency Physicians.

Healthcare workers say anyone using a portable generator should avoid placing it in an enclosed area, such as a patio or a garage.

"By doing so, you are letting a poisonous, odorless and colorless gas into your home, putting your life at risk,” said Dr. Becky Parker.

Symptoms of carbon monoxide poisoning include headache, dizziness, weakness, nausea, vomiting, chest pain, and confusion. CO poisoning is often difficult to diagnose because the symptoms mimic other illnesses, such as the flu. People should be concerned about the possible presence of carbon monoxide if more than one person living or working together develops these symptoms simultaneously over a short period of time.

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Officials urge anyone using a generator to carefully read the instruction manual. If you’re unsure of how to hook your generator up and operate it properly, check with your local fire department. You should also be sure to keep carbon monoxide detectors in your home.

For more information on carbon monoxide poisoning, click here.