New figures show there has been a sharp increase in the number of people suffering from carbon monoxide poisoning in the South East in the past five years.
Last year there were 103 cases in Hampshire, 44 in Buckinghamshire and 5 in Berkshire, while carbon monoxide poisoning has gone up by 80% in East Sussex.
Campaigners are urging people to make sure they have carbon monoxide detectors in their homes.
Jessica Newton and her son Jack were hospitalised after a gas leak from a faulty heater in their flat in Brighton.
Jessica says they were saved only by their detector.
She says: "It's the most scariest thing because you don't know it's there, you can't smell it, you can't see it. And it's one of those things you don't normally think 'oh there could be a carbon monoxide leak' and I didn't realise that having an old fireplace, you're at a higher risk of that anyway."
Statistics show on average, 50 people die in the UK from being poisoned every year, with the South East being one of the worst affected areas.
The deadly, invisible gas cannot be smelled, tasted or seen. Project SHOUT who collated the figures is encouraging everyone to make sure they have a carbon monoxide detector in their home.
- What are the symptoms of carbon monoxide poisoning and who is most at risk?
Symptoms may be hard to distinguish from other commons ailments.
Dizziness, tiredness, headaches, nausea and generally feeling unwell are common.
Carbon monoxide poisoning is commonly mistaken for other illnesses, leaving the elderly and very young most vulnerable.
The gas is known as a silent killer; due to the fact it does not have a colour, smell or taste.
- Watch Malcolm Shaw's report below