Five children and two adults in Sydney’s east have been rushed to hospital after a carbon monoxide leak which has been traced to a pool heater.

Emergency services were called to the home on Wentworth Road in Vaucluse after 1.30pm on Monday.

New South Wales Ambulance found two adults and five children suffering from nausea and dizziness.

It is understood the patients were all in stable conditions and conscious but it’s unclear who called emergency services. The seven were taken to nearby hospitals.

Fire and Rescue NSW’s crew identified high levels of carbon monoxide in the atmosphere of the home.

They traced it to a pool heating system, which runs on natural gas, identifying it as the likely source of the odourless, colourless but potentially fatal gas.

Carbon monoxide is particularly dangerous to humans because it displaces oxygen in the body which damages internal organs and the brain.

“At extremely high levels, carbon monoxide can cause death,” NSW Health’s website says.

The crew cut off the heater, a spokesman said, before ventilating the home.

The pool’s heating system will now be investigated but it’s suspected the system’s flue may have malfunctioned or a seal may have been damaged allowing the gas to leak into the home, FRNSW’s spokesman said.

The spokesman warned people to check their heating systems as winter brings lower temperatures.

“If you have a flue, make sure it’s properly installed and functioning, and have it regularly checked,” he said.

FRNSW urged people to also avoid using outdoor heaters, particularly those with external gas bottles, as indoor heaters because they produce large amounts of carbon monoxide.