Current Evidence on the Relationship Between Perioperative Hypothermia and Surgical Site Infection: A Scoping Review.

Background: Surgical site infection (SSI) is a common complication that increases morbidity, prolongs hospital stays, and raises healthcare costs. Perioperative hypothermia may contribute to its development by altering tissue perfusion, oxygenation, and the immune response. Objective: To evaluate the association between perioperative hypothermia and the risk of SSI in adult patients. Methods: A scoping review was conducted following the methodological framework of Arksey and O'Malley, expanded by Levac, the recommendations of the Joanna Briggs Institute, and the PRISMA-ScR guidelines. A systematic search was performed in PubMed and Scopus through 30 April 2026. We included observational studies and clinical trials in adults undergoing surgery that evaluated the association between perioperative or intraoperative hypothermia and the occurrence of SSI or other postoperative infectious complications. Results: A total of 28 studies were included. Retrospective observational studies were the most common design, comprising 19/28 studies (67.9%), followed by 6/28 prospective cohorts (21.4%) and 4/28 randomized clinical trials (14.3%). The studies were conducted across 12 countries, with the United States contributing the largest proportion (14/28, 50%), followed by China, Turkey, and Japan with two studies each (7.1% per country). Regarding the main findings, 14 studies (50%) reported a positive association between perioperative hypothermia and an increased risk of SSI or other postoperative infections, whereas 11 studies (39.3%) found no statistically significant association. Most studies (15/28, 53.6%) used a fixed temperature threshold of <36 °C, while a smaller proportion applied lower cutoffs such as <35-35.5 °C (3/28, 10.7%); in the remaining studies (10/28, 35.7%), the threshold was not clearly specified. Temperature measurement methods were frequently underreported (21/28, 75.0%). Among studies that did report them, approaches included repeated measurements (3/28, 10.7%), continuous monitoring (2/28, 7.1%), mean intraoperative temperature (1/28, 3.6%), nadir temperature (1/28, 3.6%), and single-point measurements (1/28, 3.6%). Conclusions: Perioperative hypothermia may be associated with an increased risk of SSI; however, the available evidence is inconsistent across surgical settings. Rather than indicating a clear independent effect, the findings suggest that hypothermia could play a context-dependent role within a broader set of perioperative factors influencing infection risk.