Everyone should have a Carbon Monoxide detector in their home. Not only should you have it, it’s the law to have one on every floor of your home. I still go in quite a few homes in the valley that do not have these installed.
They are easy to install and inexpensive to buy so there is really no excuse. The state law says that you should have one that is connected to the home wiring system and has a battery back-up. The one in the photo is probably the easiest to install. It just plugs into a socket and has a battery for back-up. Here is the link to buy it on Amazon, or you can pick one up at one of the local stores.