Fire departments in Harris County alone responded to 475 carbon monoxide calls last week, according to the county's fire marshal.
Like millions of Texans, Etenesh Mersha lost power during the storm. In order to charge her phone, she turned on her car in an attached garage, leading to suspected carbon monoxide poisoning.
"She's very nice, and her husband is very nice," said Etenesh's cousin, Yetimwuha Wolde. "She visits us every time, and she calls us every time. She brings us [gifts] every Christmas for my kids."
Etenesh left the car running, and by the time help arrived, she and her daughter, Rakeb, died. Her husband and 8-year-old son were rushed to the hospital.
READ MORE: 'We tried our best to save them,' said family of woman and 7-year-old who died from carbon monoxide poisoning
During an update issued on Wednesday, the family said Etenesh's husband is doing better. Their son remains hospitalized, but began speaking again on Tuesday.
The dangers of carbon monoxide sent hundreds to the hospital. The Cy-Fair Fire Department said first responders evaluated 49 patients for CO poisoning.
"You don't realize you're in trouble until you're quite sick," said Dr. Linda Yancey, an infectious disease specialist for Memorial Hermann. "Now, the early effects are very non-specific, you might feel a little bit of fatigue. You might have a headache."
Carbon monoxide is known as the silent killer because it's odorless and tasteless. Yancey said it's important to check your detectors on a regular basis.
"Anytime you're burning anything for heat, you're generating a small amount of carbon monoxide, and that's why they recommend that you get your furnaces cleaned and inspected yearly, that you get your chimney serviced on a regular basis," she explained.
During the storm, doctors saw cases in which patients used generators or grills inside of their homes.
READ ALSO: Tips to protect yourself from carbon monoxide poisoning
The Houston Fire Department told Eyewitness News it's important to have CO detectors on each floor of your home.
"It's going to need to be outside of each sleeping area and then on each level of your home," said Martee Boose, an HFD firefighter and department spokesperson.
Boose said you should check you CO detector monthly to make sure it's working properly and replace it every 10 years.
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