During "The Empire Strikes Back".
Summary: Luke and Han trapped one night on the Remote Ice World of
Hoth, and their own private miseries.
Excerpt:
The world had become very white, tinged with blue. Nothing else, though -- just the colors, or rather the absence of them. Nothing else existed. No sensation, no sound, no feeling at all.
Oh, the cold had grown almost boring by that time -- he was chilled to the bone even before he had gone off to investigate that meterorite, and looking forward to warming up back at Base -- as warm as he would have gotten, which wasn't much. Living as long as he did with nothing but dun sand and blue sky, and oppressive heat, his body had taken a long, long time to acclimatize to the bone-brittling insanity that was Hoth.