• environmental medicine, hypothermia
• cardiac arrest
• resuscitation
• emergency care systems

Matsuyama et al report on the characteristics and outcomes of accidental hypothermia. In total, 537 patients were finally included in the analysis, which makes it one of the largest patient cohorts on accidental hypothermia hitherto.1 Until now, most studies on accidental hypothermia focused on rural and mountain areas because it is a well-known entity in those environments. Most readers will have lively pictures in mind of persons affected outdoors by cold, for example, people being buried in avalanches, immersed in freezing water (remember the Titanic catastrophe with 1522 victims) or incapacitated by cold and frostbites to hands and feet (nearly 1 million combatants died of hypothermia in World Wars I and II and the Korean War).2 Urban accidental hypothermia in contrast is subtle, rarely visible, as people often tend to be affected indoors, and suffer from other underlying diseases, which may be more eye-catching.

Accidental hypothermia triggered by cold has been defined as primary accidental hypothermia, in contrast to secondary hypothermia, which is considered to be triggered by or at least associated with other underlying diseases (table 1). The Matsuyama study is one of the few studies assessing accidental hypothermia in an urban area, and it is only the second study reporting a predominant incidence of …