Back in 2010, I compiled two lists of Cold Fantasy (here's the one for younger readers, here's the one for older readers). I've just gone through my reviews for the last two years, and extracted more recommendations of books with which to escape from the heat.
Breadcrumbs, by Anne Ursu (middle grade), is all about the snow and ice (being a retelling of The Snow Queen, this is to be expected). The cover in itself cools one down.
And even more intense breath of arctic air comes with Icefall, by Matthew Kirby (middle grade)--what better place to be when it's 100 degrees outside than snowbound in a Norwegian fjord? Yeah, there's a murderer snowbound with you--but at least it isn't too hot.
Another beautifully cold cover is Witchlander, by Lena Coakley (YA), and there's lots of snowy good times (kind of. In an isolated, lonely way). This is one that I think needs to somehow make into the hands of more young teen boy readers, though I enjoyed it lots myself.
The Snowstorm, by Beryl Nethercliff, is an older time slip story that takes place mostly indoors ...but the titular snowstorm does make an appropriately chilly appearance!
Winterling, by Sarah Prineas, is of course all about the snow and cold--lovely! It's a good story too, perfect for handing to your wilting 11 year old.
City of Ice, by Laurence Yep, delivers what it promises, taking the reader to a place that is cold indeed, where Canadian mounties patrol the skies riding on the backs of giant birds, among other marvels.
The Crowfield Curse, by Pat Walsh, is a lovely escape into the unpleasantness of a medieval winter...in a monastery, so even chillier than one might expect! And its sequel, The Crowfield Demon, is set in medieval March, so plenty of damp chilliness and never being warm. These are middle grade, but stand up very well to reading by an adult-- I recommend both of these enthusiastically to anyone who likes good historical fantasy, not just because they make you appreciate having dry, warm, feet.
Cold Magic, by Kate Elliot (marketed to grown-ups), is described by its author as an "Afro-Celtic post-Roman icepunk Regency novel with airships, Phoenician spies, and the intelligent descendants of troodons." It's also cold, though not consistently so...If my memory serves, it gets warmer by the end. So maybe more of a September reading book.
For those who want "horror in cold weather" I suggest The Toymaker, by Jeremy de Quidt. Ostensibly for young readers, but I kind of wish I hadn't read it. It is chilling in both senses of the word.
Anyone else read any good cold books recently?