Perioperative Temperature Monitoring in Anesthesia: A Review of Current Evidence and Clinical Practice

Perioperative hypothermia remains common during anesthesia and surgery. It is associated with higher rates of surgical site infection, blood loss, transfusion, cardiac events, postanesthetic shivering, delayed recovery, and longer hospital stay. Temperature monitoring is therefore an important part of safe anesthesia care when it is linked to thermal management. This article is a narrative review of perioperative temperature monitoring in anesthesia. The aim was to review the physiology of perioperative heat loss, the clinical effects of hypothermia, the performance of common monitoring sites and devices, and the practical role of monitoring in prevention and management. A structured literature review was performed using PubMed. Search terms included combinations of "perioperative temperature monitoring," "anesthesia," "hypothermia," "core temperature," "esophageal temperature," "nasopharyngeal temperature," "bladder temperature," "zero-heat-flux," "warming," and "prewarming." Boolean operators were used to refine the search. English-language articles relevant to adult perioperative anesthesia care were reviewed. The final manuscript included 43 references, comprising randomized trials, observational studies, reviews, meta-analyses, and guideline-based articles. The evidence shows that core temperature monitoring is more reliable than peripheral or skin-based methods for detecting perioperative hypothermia. Esophageal and nasopharyngeal probes remain practical and accurate during general anesthesia. Bladder temperature is useful in selected patients, especially during longer procedures, but may be less reliable when urine flow is low. Newer zero-heat-flux forehead systems offer a useful noninvasive option across different perioperative phases, although agreement with invasive core sites is good rather than perfect. Evidence also shows that measured temperature can support timely warming or adjustment of warming, better maintenance of normothermia, and lower rates of temperature-related complications. Perioperative temperature should be measured routinely in patients at risk and interpreted together with active thermal management. The method should be chosen according to the patient, the type of anesthesia, and the stage of care. Monitoring is most useful when started early and paired with active warming and clear institutional protocols. More high-quality studies are still needed to compare newer devices, define acceptable accuracy thresholds in different settings, and determine the best monitoring pathway from the preoperative area to recovery.