When power goes out, keep your portable generator outside when using it and at least 20 feet away from the house. Never use them inside of the house, on a porch, in a garage, basement, or shed. Even if garage doors are open, CO gas can build up to deadly levels within minutes. Charcoal grills, camping stoves, kerosene lamps and heaters, and other equipment that uses fuel should never be used indoors. CO is an invisible, odorless gas that can be fatal. If you breathe in a lot of CO gas, it can make you pass out or kill you.