Interesting book idea...

[redstar.division]

I agree with Scourge, if I was willing to move the book far enough into the future than less explanation as to why the endless winter happened would be suitable. I'd like to start in the not to distant future however because I think an immediate future has more of an emotional impact and resonates more with the reader the closer to the present it is.

I'm thinking I may go the route of a nuclear winter and start the book around the year 2020 and fast forward through the attack to when the enviroment is suitable for the snow and cold to start. In the event of an all out nuclear war, the fallout would create a large population of sick people and I'm toying with the idea of something akin to the asylums of the 19th and early 20th century that many TB patients were placed in. I think this is a great setting and the urgency of the cold and snow would play a big role in the deterioration of the hospital.

[Cowutopia]

nuclear winter ought to be alternate history book, imo. Those are always fun reads.

[redstar.division]

nuclear winter ought to be alternate history book, imo. Those are always fun reads.

So instead of setting the book even just a decade or so in the future, change the events of say the Cold War or the onging India/Pakistan conflict and then create an alternate history?

I like that.

[Cowutopia]

Totally. If you want I can recommend a whole shitload of awesome alternate history reads to put you in the mood.

[redstar.division]

Yeah definitely, I already have PKD's "The Man in the High Castle" on my radar so any others you've read and enjoyed would be great.

I really like the idea of these radiation hospitals as a setting. State hospitals have always fascinated me with their underground tunnels and thick doors. For years I've had this idea of someone walking down one of the tunnels when the power fails and they hear noise approaching from both sides, this seems like it could work well within the context of this story.

[Scourge]

I definitely like the idea of an alternate history story.

[Some Stupid Japanese Name]

Read anything by Harry Turtledove if you like Alternate History.
Pastwatch by Orson Scott Card is fantastic as well.