Travels with my cheap ebook reader

While eink is a wonderful invention, one problem it has is that low temperatures slow it down.
When I took my Cybook Gen3 reader, the cheapest and the best in my view, up the Eiger on a recent climbing holiday, it was noticeable how when reading at sub-zero temperatures, the page turns slowed remarkably.
The ebook reader still worked fine, it was just slower.

There have been reports of ebook readers, whether cheap or not, ceasing to function altogether in the cold weather, but I’ve never had this experience on any of my ebook readers and suspect that the ebook readers concerned must have been faulty.