The signs your heater is putting you at risk of carbon monoxide poisoning.

It’s official: July has begun and a hoodie, ugg boots and trackies just aren’t cutting it anymore.

Now that we’re well and truly in the cruel, cruel grasp of winter, many of us are cranking up our heaters.

But before you go and fill your home with much-needed warmth, there are some things you need to keep in mind. Yes, sure, ridiculous gas and energy prices. But on the top of the list? Carbon monoxide poisoning.

If that sounds dark and scary, don’t worry, there are some ways you can proof your home from hidden nasties.

What on earth is carbon monoxide poisoning?

Carbon monoxide is a colourless, odourless gas that is thought to cause approximately 365 public hospitalisations in Australia annually. Because the substance is undetectable to the human body, and can be emitted by a range of everyday products from barbecues to gas heaters, many people are at risk every day.

Carbon monoxide poisoning can manifest in a range of symptoms, including tiredness, shortness of breath, headaches, dizziness, nausea, weakness, confusion, and chest pain.

And the worst case scenario is devastating.

Longterm, carbon monoxide poisoning can result in loss of consciousness, heart disease, brain damage, and, ultimately, death.

Australian comedian Fiona O'Loughlin spent four weeks in a coma after unwittingly falling victim to her faulty heater. After weeks of silent toxification, she was given just a 7 per cent chance of survival.

"It went over the course of a month. I forgot things, I thought I was getting early Alzheimer’s. I was forgetting things, forgetting my kids’ names," she told Gold104.3’s Jo & Lehmo.

Thankfully, O'Loughlin went on to make a full recovery.

Earlier in the year, Mamamia also reported on the deaths of Andrew, Anne and Richard Basnett from New South Wales, who were thought to have lost consciousness before losing their lives in quick succession of one another.

How can I protect my family?

One of the most important things to do is to ensure your gas heater is professionally serviced every two years. If it has recently been serviced, but is still showing any sign of trouble, you should get it checked again immediately.

Signs of danger include an unusual yellow or sooty flame, the pilot light going out unexpectedly, or ‘popping’ or ‘banging’ when lighting, the surrounding walls becoming too hot to touch while the heater is on, or the presence of soot stains around the heater.

It's highly advisable to have plenty of ventilation when using a gas heater, as this allows fresh air to flow in and fumes to flow out. In light of this, don't seal up doorways, windows, or nearby vents.

Always avoid using your heater in closed spaces like the bathroom, bedroom, or caravan. As an extra precaution, purchase a carbon monoxide alarm from your local Bunnings or other DIY store.

Last of all, if a product or appliance is designed for the outdoors, you should never bring it inside for indoor use.

The golden rules? Don't mess around - get your heater serviced. And when in doubt? Call in a professional.

For more information, visit VicHealth here or Product Safety Australia here.