Cooling vests for surgeons: heat stress under gowns and lead aprons
Cooling vests worn under surgical gowns can make surgeons noticeably more comfortable. In a 2023 randomized crossover trial of 30 orthopedic surgeons, an ice-pack vest cut thermal discomfort by 2.1 points on a 10-point scale and reduced perceived sweating and fatigue, without changing core temperature or cognitive test scores. Vests using ice or phase-change packs suit sterile attire best.
Why do surgeons overheat in a cold operating room?
Surgical gowns are designed as barriers, and barriers insulate. The 2023 trial authors note that heat transfer and evaporative cooling are restricted by insulating surgical gowns, and that rooms kept near 20°C (68°F) may not provide enough cooling under multiple layers of protective equipment. Add physical effort, surgical lights and long cases, and heat builds up even when the rest of the team is cold.
Lead aprons make it worse. A 2026 model-based study in Atmosphere predicted that 75% of male surgeons wearing 7.5 kg lead aprons would be dissatisfied from heat in a room at 20.5°C, while some anesthesia staff in the same room would be cold.
Sweat under a gown is more than a comfort problem. It soaks scrubs, makes gloves harder to manage and adds to fatigue over long lists. Heat also varies by specialty and case type: orthopedic, spine and interventional procedures often combine physical effort, long duration and lead, which is why much of the research focuses on these groups.
What did the randomized trial find?
Byrne and colleagues published a randomized crossover trial in Occupational and Environmental Medicine in 2023. Thirty orthopedic surgeons in the United States performed 120 operations, with and without a cooling vest that placed ice packs over the shoulders, back and flanks under their protective equipment.
The vest reduced thermal discomfort by 2.1 points on a 0 to 10 scale. Mean skin temperature fell by 0.23°C, while core temperature did not change significantly. Surgeons reported less sweating, less fatigue and lower perceived exertion. Cognitive tests of processing speed and visual memory showed no difference, so the benefit was comfort rather than measurably sharper thinking.
A separate trial, registered as NCT04511208 under the title Cooling Vest May Reduce Heat Stress During Surgery, reflects continuing research interest in this question.
| Outcome | Effect of cooling vest |
|---|---|
| Thermal discomfort (0 to 10) | Reduced by 2.1 points |
| Mean skin temperature | Reduced by 0.23°C |
| Core temperature | No significant change |
| Perceived sweating and fatigue | Reduced |
| Cognitive test scores | No difference |
Does heat affect surgical performance?
Evidence is mixed. A 2019 study in PLOS One exposed 17 surgical staff to a simulated burn surgery at 34°C versus 23°C. In the hot condition, core temperature and heart rate rose, and sweat loss reached about 0.6 to 0.8 kg compared with about 0.2 kg in the control condition. Dexterity scores showed a trend toward impairment that did not reach statistical significance.
Together with the cooling vest trial, this suggests that heat clearly affects comfort, sweating and fatigue, while effects on measured performance are harder to demonstrate in short studies. Sweat is also an infection-control concern under a sterile gown.
Which types of cooling vest work under a gown?
Cooling vests work in different ways, and not all suit sterile attire.
Ice-pack vests: frozen packs in pockets deliver strong cooling; the trial used this design. Packs need a freezer and are replaced as they melt.
Phase-change vests: packs that solidify at a set temperature, often above freezing, give steadier, gentler cooling and can feel less harsh on skin.
Evaporative vests: rely on water evaporating from the fabric, which is limited under an impermeable gown and can add moisture.
Active systems: fans or circulating fluid add hardware and tubing that can complicate sterile workflow.
How to choose and use a surgeon cooling vest
Look for a low profile that fits under a gown and lead apron without pressure points, pockets positioned over the upper back and shoulders, and packs that last for the typical case length. A thin fabric layer between pack and skin helps avoid discomfort from very cold packs.
Put the vest on before gowning, since it cannot be adjusted once you are sterile. Check with your facility about approved products and any laundering requirements, as vests worn under scrubs fall under personal clothing policies. Surgeons who experience dizziness, palpitations or other symptoms in the heat should talk to a clinician.
Plan the logistics before buying. Ice and phase-change packs need freezer or refrigerator space near the operating rooms, a system for labeling and cleaning packs, and a routine for swapping them between cases. A department-level approach, with a shared freezer and spare packs, often works better than individual surgeons managing their own supplies.
Cooling for surgeons, warmth for the team
A cooled surgeon may accept a warmer room setting, which helps anesthesia and nursing staff who feel cold. Cooling vests and warm layers are complementary tools for the same operating room.
Key takeaways
Surgical gowns and lead aprons trap heat, so surgeons can overheat in rooms near 20°C.
A 2023 randomized trial found cooling vests reduced discomfort, sweating and fatigue without changing core temperature or cognition.
Ice and phase-change vests suit sterile attire better than evaporative designs.
Cooling the surgeon can allow a room setting that is kinder to cold team members.
Frequently asked questions
Do cooling vests work for surgeons?
A 2023 randomized crossover trial of 30 orthopedic surgeons found that an ice-pack cooling vest reduced thermal discomfort by 2.1 points on a 10-point scale. It also reduced perceived sweating and fatigue.
Can you wear a cooling vest under a sterile gown?
Yes. Vests are worn under scrubs or over the scrub top and under the gown, and must be put on before gowning. Check your facility's personal clothing and laundering policy.
Do cooling vests improve surgical performance?
The 2023 trial found no difference in cognitive test scores with the vest. The main demonstrated benefits were comfort, less sweating and less fatigue.
Which cooling vest is best under a lead apron?
Low-profile ice or phase-change vests that avoid pressure points under the apron's weight are usually most practical. Evaporative vests work poorly under impermeable layers.
How long do surgeon cooling vest packs last?
It depends on the pack type, room temperature and workload. Many users keep spare frozen packs available for long cases and swap them between procedures.
Related reading
Sources
Cooling vest improves surgeons' thermal comfort without affecting cognitive performance: a randomised cross-over trial, Occupational and Environmental Medicine, 2023 (PMC)
One Operating Room, Two Thermal Worlds: Determinants and Limits of Thermal Comfort for Surgical Staff, Atmosphere (MDPI), 2026
Cooling Vest May Reduce Heat Stress During Surgery (NCT04511208), ClinicalTrials.gov
About HEATJAC. HEATJAC is a thermal architecture company founded by an anesthesiologist. We design patented garment systems that capture, conduct and broaden warmth across the body, and we publish this knowledge hub because the science of staying warm should be public. HEATJAC products are not medical devices and are not intended to diagnose, treat, cure or prevent any disease.