Five people treated for suspected carbon monoxide poisoning from indoor BBQ

Five people have received a sickening lesson on why barbecues shouldn't be used indoors after suffering suspected carbon monoxide poisoning.

Three women and two men, aged from teenagers to their 50s, had headaches and nausea and called paramedics last night after their Queen's Birthday barbecue in Campbellfield.

They were taken to the Royal Melbourne and The Northern hospitals in a stable condition, paramedics said.

Emergency services were told the barbecue had been on for about four hours.