TIL that the infamous (Sylvia Plath) suicide technique of sticking one's head in an oven was not a hot, violent affair. Rather, ovens used to run on "town gas" that had high carbon monoxide, and putting your head in an unlit oven was a rather peaceful way to go.

https://en.wikipedia.org/wiki/Coal_gas

https://www.reddit.com/r/todayilearned/comments/15d2reo/til_that_the_infamous_sylvia_plath_suicide/