On rereading this recently, I was struck by two things; one was how well this book has aged. Granted, it has many flaws, most of which LeGuin addresses herself in forwards to some newer additions. It's oddly heteronormative, and takes male for default in a way which is just annoying, and can only partly be attributed to Genly Ai's narrative voice. However, LeGuin acknowledges these faults and in fact has written several short stories trying to address them, so I'm just going to mention them and let them go.

But I think the book has aged well because, although first published in 1969, this book remains one of the most creative re-imaginings of gender in the field of SF. It's still the yardstick by which we measure other books on the topic.

The second thing I was struck by, though, was LeGuin's depiction of cold. Approximately the last third of the book is a polar trek, and the whole of the book takes place in conditions not much warmer than a Siberian summer, so it's not too incredible that there would be a lot of cold in it, but LeGuin gets cold in a way that I've seen other writers fail at. She gets that the enemy of warm isn't cold, it's damp, and that the technique for staying warm involves addressing the challenge of trapping the heat the body produces without trapping the moisture. She gets the way everything turns fragile in the cold, and the way you can be warm for only so long as you keep moving. She gets the way that sleeping cold is almost as bad as not sleeping at all, and the calories the body needs to stay warm. I wonder if she's lived somewhere this cold, or if she read polar exploration accounts, or if she is merely very, very smart.

Any time you want to know what cold is like, this book is a good source.