What are the typical temperature and humidity ranges recommended for the operating room?

• A. 60-65°F and 40-60%
• B. 75-80°F and 20-30%
• C. 65-70°F and 70-90%
• D. Temperature around 68-73°F (20-23°C) and humidity roughly 30-60% (often around 50%)

Answer: (D)

Maintaining a stable operating room environment is essential for patient safety, staff performance, and equipment integrity. The typical target is around 68–73°F (20–23°C) with relative humidity in the 30–60% range, often near 50%. This balance keeps the room comfortable for lengthy procedures, helps prevent patient hypothermia by allowing warming measures to work effectively, reduces static electricity that can interfere with equipment and vapors, and limits condensation and microbial growth that can occur with too high humidity.

The cooler range (60–65°F) tends to be on the cool side for both patients and staff and isn’t as effective for preventing hypothermia, even if humidity levels are acceptable. The warmer, drier option (75–80°F with 20–30% humidity) can make the environment uncomfortable and increases static electricity and mucosal dryness. The highly humid option (70–90% humidity) creates condensation risks, promotes mold and corrosion, and can foster microbial growth, all of which are undesirable in an OR.