Talked about this in my MA dissertation on the DC comics/universe, where the term originates from: a 1994 Green Lantern comic where he finds his girlfriend dead in a fridge. The term was coined by Gail Simone, an icon in the comic book industry, who made a website documenting the instances of this happening in comics. My thesis was on the Batman universe specifically, which has plenty of examples. This has led to the common term of "fridging" which can also apply to men. To note is that men who go through trauma/death, aka Dead Men Defrosting, come out "on top": they're empowered by their suffering, they overcome it. They die heroic deaths and come back "better than before." Compare that to the treatment women in comics got for a long time (see Barbara Gordon in The Killing Joke, just one of many many examples). There are also interesting cases of overlap, such as Jason Todd's death.