Ebenezer Scrooge's hallucinations caused by hypothermia?

Ebenezer Scrooge may not have been as weatherproof as he thought. The bitter winter is described vividly in A Christmas Carol, but Scrooge maintains just a low fire to warm himself in his room and eats only gruel. Dickens tells us “he carried his own low temperature always about with him”. ​

However, his economies with the heating may have backfired on the old miser. While Scrooge initially suspects his ghostly visitors may be the result of a poor digestion, he does not appreciate that hypothermia can also produce vivid hallucinations.​

“A combination of undernutrition and hypothermia is as likely an explanation of the delirium as any,” concludes a tongue-in-cheek study of Scrooge’s case in the Journal of the Royal Society of Medicine.​

There are similarities with other cases. In 2008, the BMJ reported on a couple who had recently converted to Buddhism, who both hallucinated that they saw a Buddhist holy man in the Cairngorms during cold weather. Climbers on Everest have described hallucinating benign companions, presumed to be due to a combination of hypothermia and the thin air. ​

One person’s hallucination is another’s apparition. And, whether or not they were the result of hypothermia, Scrooge’s ghostly visitors were certainly a blessing.​