Two adults and nine children are being treated in a Tasmanian hospital after suffering carbon monoxide poisoning.

The ABC reported two adults and five children are in a serious condition in Royal Hobart Hospital after using an open charcoal grill inside a residence in South Hobart.

Four other children are being monitored.

The children range in ages from 2 months to 17 years old.

Hobart’s Mercury newspaper reported four Ambulance Tasmania units attended a Triple 0 call about 2.30am and paramedics treated patients at the scene before transporting them to hospital.

Tasmania Fire Service Station Officer Adam Doran said a high reading of carbon monoxide was recorded in the downstairs area of the two-storey house, where the grill was being used.

“(It was) up over 200 parts per million which does get into that dangerous situation where you can get nausea, vomiting and shortness of breath,” he told ABC Radio.

“It was starting to get to a point where it would have been highly toxic and dangerous for the occupants.”

Carbon monoxide gas, which is created by burning any fuel including gas, oil, coal or wood, has no odour or colour but can be fatal.

“It’s not easy for people to recognise when this might be happening to them,” Mr Doran said.

“If you’ve got a cooker that’s designed for outside, then it must only be used outside.”

Symptoms of carbon monoxide poisoning include headaches, nausea, dizziness, fainting, shortness of breath and confusion.

The state’s health department warns against using outdoor barbecues, charcoal grills and heat-bead stoves indoors or in enclosed spaces like caravans and boat cabins.

-with AAP