A characteristic rotten egg smell, hissing noises near gas appliances or lines, and symptoms like weariness, nausea, or dizziness are all indicators of a gas leak. Take these immediate actions if you think there may be a gas leak: - Quickly leave your house, keeping the doors and windows open. - Avoid using any electrical appliances that could spark, such as light switches and phones. - Avoid attempting to locate the leak's origin. - Report the alleged leak by dialling the emergency line for your gas company. - Await the arrival of emergency responders or gas company staff before taking safe action.