This idiom describes a sudden loss of courage, confidence, or resolve, often at a critical moment before committing to an action, such as a major decision, marriage, or performance. It suggests nervousness or doubt that causes hesitation or withdrawal, evoking the physical sensation of coldness from fear or anxiety. The phrase is used in both serious and lighthearted contexts to express reluctance or second thoughts, often with a sympathetic or teasing tone.

The phrase likely originated in 19th-century English, possibly from military contexts where soldiers’ cold feet (from fear or literal cold) made them reluctant to advance. An early metaphorical use appears in Stephen Crane’s 1896 novel *Maggie: A Girl of the Streets*, where a character ‘gets cold feet’ before a fight. Another theory links it to gambling slang, where a player ‘with cold feet’ lacks the nerve to bet. The phrase gained prominence in the early 20th century, particularly in American English, during discussions of weddings, where ‘cold feet’ became synonymous with bridal jitters. Its use in literature, such as F. Scott Fitzgerald’s works, and later in pop culture, cemented its place in modern English.