The prevalence of cold-related complaints and symptoms in the general population has remained unknown. As part of the nationwide FINRISK 2002 health survey performed in Finland, 8,723 people aged 25-64 years filled in a questionnaire asking about the number of hours spent weekly in cold air, their sensations during cold exposure, cold-related complaints, symptoms of diseases, and degradation of performance. Cold thermal sensations at +5 degrees C to -5 degrees C were reported by 35% of men and 46% of women. Almost all subjects reported at least some cold-related complaints, most commonly musculoskeletal pain (men 30%, women 27%), followed by respiratory (25% / 29%), white finger (15% / 18%) and episodic peripheral circulation symptoms (12% / 15%). Decreased mental or physical performance in cold was reported by 75% of men and 70% of women, most commonly impairing manual dexterity and tactile sense. With declining temperature, the first symptom to emerge was pain in the elbow or the forearm (at -3 degrees C), followed by increased excretion of mucus from the lungs (-5 degrees C), while most other symptoms appeared only at lower temperatures of -15 degrees C to -20 degrees C. Most symptoms showed little or no association with the weekly duration of exposure, with the exception of cold-induced pain at most sites. Although, in general, Finns are well adapted to the cold climate, the high prevalence of cold-related complaints poses a challenge to the health care system in terms of decreased performance and the possibility that such symptoms predict more serious health effects, such as increased mortality.