Open all doors and windows to ventilate the room – The first thing you should do is open and window or door you can to get some fresh air inside. Find the nearest door to you and do it straight away. This will lessen the concentration of gas in the air and make it easier to breath
Remove people and pets from the area - Getting everyone inside the house to safety is key here. Helping family members to a sheltered place outside away from the gas leak is priority. Ensure all pets have been removed and everyone in the house has been accounted for
Turn off all ignition sources – IF you have any flames in your home make sure they are turned off (Cookers, Stoves) Ensure any smokers in the house do not light up cigarettes
Isolate the gas supply to your home – You can find the gas shut off valve to your home located on the gas meter. If you know where your gas meter is and can safely access the area, then shut off your gas supply. This will stop the gas leak from getting worse.
Call for help – Call a plumbing professional who specialises in gas leaks and tell them you have an emergency. They will fully understand your position and will arrange for a qualified plumber to attend and get your leak found and fixed.