It's fairly common for hunters to use LP gas appliances in their cabins, but these deaths are serving as a tragic reminder to be careful..
Small traces of carbon monoxide usually form with LP gas appliances, but if it isn't working right, it can build up and be released into the air.
Special care also needs to be taken with the LP tanks.
"They need to be stored outside, if they're using it in a cabin it needs to be well-vented, ventilated heaters, they need to make sure they do have CO detectors," says Diana Schlicher, of LPG Service and Gifts in Mosinee. "So that they can make sure there is no carbon monoxide going on."
Carbon monoxide is a colorless, odorless gas, and even small amounts of it can be dangerous.
Watch out for flu-like symptoms, like headaches, nausea and dizziness.