New Ulm, MN – NEW ULM — Arnold Schweiss, 93, of New Ulm, knew one thing for sure Tuesday morning.

“We are glad to be alive,” he said when he answered his cellphone from a room at Hennepin County Medical Center.

Schweiss, his wife, Velma, and stepson, Steve Harder, were being treated for carbon monoxide poisoning at the Minneapolis medical center’s hyperbaric unit after a health scare at their home Monday.

A high level of carbon monoxide was found about 9 a.m. Monday at the Schweiss residence on the 1000 block of North Broadway.

Harder was scheduled to be released from HCMC Tuesday afternoon, said Lisa Hagen of Redwood Falls, the Schweisses’ daughter.

Velma Schweiss checked out OK on Tuesday morning but is staying at HCMC while doctors continue to monitor her husband’s heart for possible problems from the poisoning.

The Schweisses and Harder were feeling dizzy and nauseous when they awoke Tuesday.

New Ulm Police Sgt. Steve Depew said snow had drifted over a furnace exhaust vent on the side of house, which possibly caused trapped CO to flow into an air intake pipe.

The residence, which also houses Schweiss’ business, did not have a carbon monoxide detector.

“They are very fortunate it happened later at night and that they woke up feeling sick. It could have been tragic,” Depew said.

In December, carbon monoxide poisoning killed two rural Springfield residents Nathan Scott Potter, 30, and Adam Lloyd Philip Jensen, 23. The deaths were ruled accidental by a medical examiner and the investigation concluded a damper on the furnace in the home was not functioning properly.

Carbon monoxide incidents increase by more than 10 percent during the winter months and is often called the silent killer, according to Centerpoint Energy’s website.

CO is a colorless, odorless, tasteless gas and when inhaled, it enters the blood stream preventing proper absorption of oxygen, which can lead to illness and even death.

According to the National Fire Incident Reporting System, municipal fire departments across the country respond to more than 60,000 CO incidents each year. The Minnesota Department of Health says about 14 Minnesota residents die from unintentional CO poisoning every year.

State law requires carbon monoxide detectors be placed within 10 feet of all bedrooms.