Charleston, SC – Roper St. Francis Hospital is currently treating 12 patients for carbon monoxide poisoning believed to be related to the use of generators.

Of those 12 patients, six had a critical level of exposure while the others had less severe exposure. All of their conditions have improved under treatment at the hospital, officials said Sunday.

The patients are being treated by Dr. Lance Davis, who is considered an expert in the field.

Carbon monoxide poisoning has been a concern of many medical professionals in the wake of Hurricane Matthew and related power outages.

South Carolina Gov. Nikki Haley spoke about generator use during a Sunday morning update on the state’s recovery from the hurricane. She said she heard local retailers have been selling a lot of chainsaws and generators.

“Please do not put the generators in your garage,” Gov. Haley said. “We say that over and over again, but we want everyone to understand the importance that there is a high risk of carbon monoxide poisoning if you do that.”

There have been no deaths in South Carolina reported yet from carbon monoxide use. But, there have been two deaths recorded in the state related to flood water.