the.com/cold sweat

means Clammy perspiration brought on not by heat but by fear, pain, or nervous shock.

from A straightforward compound of 'cold' and 'sweat,' first used to describe the specific chilly, damp perspiration that comes with fright or faintness rather than exertion — your body's thermostat getting its signals crossed under stress. English writers were already using the phrase this way by the medieval/early modern period, and it stuck because it names something everyone recognizes: sweat that has nothing to do with being warm.