A double-glazed window keeps the heat in your house because air is such a good thermal insulator. To escape from your house, heat has to travel through the inside pane of glass, through the sandwiched air, and then through the outer pane to the outside.
It was this technology that ensured that the Norwegian Roald Amundsen - and not Captain Robert Falcon Scott - won the race to the South Pole, on December 14, 1911. Not that he used double-glazing, but each of his 97 sledge dogs had a thick coat of fur that trapped their body heat in its fibres. This warmed air "double-glazed" the dogs so that they lost heat slowly, and each hair was hollow, so that the air in the fibres acted as a further barrier heat loss. The dogs slept in the open - and two died of cold in their sleep - but when Amundsen made his final bid for the pole, his men travelled on four sledges, each drawn by 13 dogs, and could at times simply let the dogs do the work. By contrast, Scott relied on sledges dragged by manpower, and as his men weakened, their progress declined. Not that Amundsen was sentimental about his sledge dogs.
For the final dash, he and his men slaughtered 24 to feed the remaining 18.
Arriving at the pole, the surviving dogs feasted on seal blubber.