Objectives: Severe infection is a frequent cause of admission to an acute medical unit (AMU). However, not all infected patients present with fever. The aim was to assess differences in 30-day mortality among patients hospitalized with community-acquired severe infection presenting with hypothermia, normothermia or fever.

Methods: A retrospective single-center follow-up at an AMU from August 1, 2009 to August 31, 2011. Patients were included the first time they presented with severe infection within the study period. Temperature was categorized into hypothermia (38.0ºC). Severe infection was defined as a discharge diagnosis indicating infection combined with organ failure within the first 24 h after arrival. Multivariable Cox regression analysis was computed to assess the association between temperature and 30-day mortality.

Results: A total of 2128 patients with severe infection were included. 3.0% (N = 64) were hypothermic, 57.1% (N = 1216) normothermic and 39.9% (N = 848) had fever at arrival. Crude 30-day mortality was 16.1% (N = 342, 95%CI 14.5–17.7%); 37.5% (N = 24, 95% CI 25.7–50.5%) for hypothermic patients, 18.3% (N = 223, 95%CI 16.2–20.6%) for normothermic patients and 11.2% (N = 95, 95%CI 9.2–13.5%) for patients with fever. Compared to normothermic patients, the adjusted hazard ratio of 30-day mortality among hypothermic patients was 1.62 (95%CI 1.06–2.49) and 0.74 (95%CI 0.58–0.94) among patients with fever.

Conclusions: Over half of the patients admitted to an AMU with severe infection were normothermic at arrival. Hypothermia was associated with an increased risk of short-term mortality, whereas patients with fever were associated with a lower risk compared to those with normothermia.