For AluBook owners, hereafter is a photo taken from the website of "L'odyssée Sibérienne" (Siberian Odyssey) (an adventure aiming to motivate people to preserve nature and environment, thanks to Lionel for the news).
The photo shows Nicolas Vanier testing the limits of his PowerBook in a industrial fridge in order to validate his notebook before bringing it with him towards Siberia and its polar temperatures. This is of course way below the official certifications provided by Apple (from 10°C).
