There's a new warning about the dangers of carbon monoxide poisoning over the summer months.
Between May and September 2014, the National Grid says it was called out to 9,500 cases related to carbon monoxide poisoning.
Now the Gas Safe Register is urging people to get their appliances checked.
Carbon monoxide is odourless and, without a proper alarm, very difficult for the public to detect.
However, it can cause serious illness and death in high concentrations.
The gas made headlines recently following the deaths of two young British children in Corfu.
Carbon monoxide (CO) is a by-product of burning gas without a sufficient air supply.
We called out a gas engineer and they condemned the property within minutes. They asked us to open all the windows and told us there were high levels of carbon monoxide present in the property
Jade Ullrich
That means badly fitted and poorly maintained boilers, ovens and other gas appliances can start to produce and leak the gas.
While it's not actually toxic, human beings can't breathe it.
When carbon monoxide fills a room, it slowly suffocates those inside and in 2014 62 households a day were affected.
Jade Ullrich is 23 and has two young children. Her family were victims of CO poisoning after moving into a property in Newquay, Cornwall.
She and her family began to suffer from extreme dizziness, tiredness and sickness.
An emergency gas engineer was called out, and condemned their boiler as "immediately dangerous".
Carbon monoxide alarms are a legal requirement in all new homes in Northern Ireland.
In Scotland alarms have to be fitted when new boilers or gas appliances are installed.
At the moment landlords don't need to provide a carbon monoxide alarm but there is legislation being put forward which means it could become law in England and Wales from October.
Sarah told Newsbeat: "Landlords have a responsibility to make sure that gas appliances are checked in the home every year.
"If you live in a rented property it's really important to say you'd like a copy of the gas safety record [because] it shows they have been checked."