The MFB says it’s lucky none of the five people who became ill while cooking a barbecue indoors weren’t killed.

Paramedics were called to the Campbellfield home last night to learn the gas barbecue had been going for about four hours.

Five people, from teenagers to people aged in their 50s, had suffered carbon-monoxide poisoning.

Three people were taken to Northern Hospital and two went to the Royal Melbourne Hospital, all with headaches and nausea.

MFB Commander Bob Lannigan told 3AW News it could have been a lot worse.

“It had the potential to make these people very ill and – worse case scenario – there could’ve been a fatality,” he said.

“It’s a colourless, odorless and very toxic to humans.”

By Pat Mitchell