According to medieval physiology blood was naturally hot and so this phrase refers to an unnatural state in which someone can carry out a (hot-blooded) deed of passion or violence without the normal heating of the blood.
Related Idioms :
catch a cold = catch cold
become infected with a cold
encounter trouble or difficulties, especially financial ones – informal
2001 - Financial Times - Most observers expect house prices to rise depending on whether the UK economy continues to grow smoothly or whether it catches a cold from the US.
as cold as charity
poor or inadequate consolation
This expression, together with the previous idiom, reflects a traditional view that charity is often given in a perfunctory or uncaring way. The words cold (as the opposite of encouraging) and comfort have been associated since the early 14th century, but perhaps the phrase is most memorably linked for modern readers with the title of Stella Gibbons's 1933 parody of sentimental novels of rural life, Cold Comfort Farm.
loss of nerve or confidence
in the cold light of day
when you have had time to consider a situation objectively
the cold shoulder
a show of intentional unfriendliness
The verb cold-shoulder, meaning reject or be deliberately unfriendly, comes from this phrase.
go cold turkey
suddenly and completely stop taking drugs
The image is of one of the possible unpleasant side effects of this, involving bouts of shivering and sweating that cause goose flesh or goose pimples, a bumpy condition of the skin which resembles the flesh of a dead plucked turkey.
have someone cold
have someone at your mercy - US informal
1988 - Rodney Hall - Kisses of the Enemy - He waited in his office for news of violence, knowing that then he would have the troublemaker’s cold.
leave someone cold
fail to interest or excite someone
left out in the cold
pour cold water on = throw cold water on
be discouraging or negative about a plan or suggestion
1998 - New Scientist - When I put it to the health minister, that perhaps all clinical trial results should be published, she threw cold water on the idea.