The 13 people, including five children, were treated at a hospital in Whitehall and are recovering. Ten of those sickened lived in the home. A police officer from Arcadia and two emergency medical technicians were among those treated for carbon monoxide poisoning.
Willis Breska, who rents out the home north of Arcadia, said it's hard to believe something like that could happen.
"They are my tenants in there, and I talked to them about the heat when we went over the contract," Breska, who lives nearby, told the Eau Claire Leader-Telegram.
Authorities said the tenants were using a charcoal grill inside the house as a heating source.
"There is an LP (liquefied petroleum) tank there, but it was empty. They didn't tell anyone about it though. I was just over there the other day, and they didn't say a thing; they should have," Breska said.