Why are operating rooms so cold?
Operating rooms in the United States are typically maintained between 68 and 75°F (20 to 24°C), the range set by ASHRAE Standard 170 and reflected in AORN guidance, with humidity controlled alongside. In practice many rooms run at the cool end or below it by formal exception, primarily for the comfort of the gowned surgical team working under lights.
Who is the room cold for?
Not everyone in an OR experiences the same temperature. A surgeon in a sterile gown under surgical lights runs hot. The anesthesia professional, circulating nurse, and technologists, who wear a scrub layer and move less, experience the same room as genuinely cold across cases that can run for hours. The temperature is a compromise, and the non-gowned team usually absorbs the cold side of it.
Is the cold for infection control?
Mostly no, and this is a common misconception. The temperature range exists for staff comfort, equipment, and overall environmental control; infection control in the OR is managed primarily through air filtration, air changes, positive pressure, and sterile technique rather than by keeping the room cold. Patient temperature is managed separately and actively, because keeping patients normothermic is a clinical priority.
How do OR staff cope with the cold?
The realistic options are limited by the environment: outer layers can be restricted by facility policy, and anything worn must not interfere with movement, hygiene, or the sterile field. Common strategies include approved warm-up jackets where policy allows, layering under scrubs, staying dry, warm breaks between cases, and low-profile warming layers worn beneath the scrub layer. Cold that degrades comfort for hours at a time is a fatigue factor, and departments increasingly treat staff thermal comfort as a workforce issue rather than a personal one.
FAQ (ADD FAQPAGE SCHEMA, SEE SETUP 3.3)
What temperature are operating rooms kept at? U.S. standards set 68 to 75°F (20 to 24°C) per ASHRAE Standard 170, with AORN guidance aligned. Individual rooms may run cooler under documented facility policy.
Are cold operating rooms more sterile? Room temperature is not a primary infection-control mechanism. Filtration, air changes, pressure relationships, and sterile technique do that work; the temperature range serves comfort and equipment.
Why do surgeons want the OR cold? Gowned surgeons work under surgical lights in impermeable sterile layers and overheat easily. The room is cooled for the hottest person in it, which leaves the rest of the team cold.
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