Recently I've had an experience with a minor gas leak that's left me afraid to even use my furnace. I have a gas furnace, and I live in a rental. The furnace works, but for the first hour of it being on I can smell gas. It's enough that a carbon monoxide detector will go off nearby.

One day I told my partner that I've been feeling super groggy and cloudy-headed for a few months, and we narrowed down the time frame to when I moved into my place. Sure enough, I switch to using a small space heater and two weeks in I'm feeling better than ever before. I 100% attribute the fogginess in my brain to the gas leak. It wasn't enough to cause an explosion, but it doesn't take much to cause serious health problems.

Here's a great video on the topic by Climate Town, an awesome educator on climate change: https://www.youtube.com/watch?v=hX2aZUav-54