Evaluating Nursing Performance During Heatwave Simulations: Protocol for a Repeated Measures Cross-Over Study

As the planet warms, extreme heat is becoming a more frequent and intense reality, reshaping the environments where people live and work. For healthcare systems, this shift presents a unique and growing challenge. Hospitals are designed to care for the sick, often housing patients who are already vulnerable to temperature changes. Yet, the staff who work within these walls—nurses, doctors, and support workers—must also contend with rising indoor temperatures while performing tasks that demand both physical stamina and sharp mental focus. When the air inside a hospital ward becomes uncomfortably hot, it does not just make people feel sweaty; it can strain the body's ability to regulate its own temperature and cloud the mind's ability to react quickly. This is a critical concern because the safety of patients often depends on the precision and alertness of the staff attending to them. If heat makes a nurse slower to notice a change in a patient's condition or less steady when administering medication, the consequences can be serious. Understanding exactly how heat affects these professionals, and what simple measures might help them stay safe and effective, is a vital step toward building hospitals that can withstand a changing climate.

A team of researchers at the University of Southampton in the United Kingdom has designed a study to investigate this very question. They aim to understand how heat stress impacts the performance of registered adult nurses and whether a simple, low-cost intervention like an electric fan can help. The study, which is currently in the planning and recruitment phase, will take place inside a specialized climate-controlled room at Southampton General Hospital. This room allows scientists to recreate specific weather conditions with high precision, something that is nearly impossible to do in a real, busy hospital ward where temperatures fluctuate and patient needs vary unpredictably.

The researchers will invite healthy, registered nurses to participate in a series of five separate sessions. In each session, the nurse will enter the climate chamber, which will be set to one of five different environmental conditions. These conditions range from a cool, standard hospital temperature of 18 degrees Celsius to a very hot 34 degrees Celsius, which reflects temperatures recorded in some UK hospital wards during recent heatwaves. The study also includes a "warm" condition at 26 degrees, which aligns with current safety guidelines for keeping rooms cool. To test the effectiveness of a practical cooling strategy, two of these conditions will include the use of an electric fan blowing air at a speed of 3.5 meters per second. The order in which the nurses experience these different temperatures will be varied to ensure that the results are not simply due to practice or fatigue from previous visits.

Once inside the chamber, the nurses will undergo a carefully structured simulation of a typical work shift. Before the main simulation begins, they will perform a short period of light exercise on a stationary bike while solving math problems. This is designed to mimic the physical and mental demands of a nursing shift and to induce a state of mild fatigue, ensuring that the study tests how heat affects tired workers, not just fresh ones. Following this, the nurses will enter a simulated hospital ward environment within the chamber. Here, they will interact with six different simulated patients, portrayed by trained researchers. The tasks will include routine duties such as checking vital signs, managing medication, and communicating with patients. Crucially, the simulation will also include two emergency scenarios where the nurse must perform cardiopulmonary resuscitation, or CPR, on a manikin. These emergency moments are designed to test physical performance under pressure.

Throughout the entire process, the researchers will measure a wide range of factors to see how the nurses are coping. They will track the nurses' core body temperature using a small capsule swallowed before the session, which transmits data wirelessly. They will also monitor skin temperature, heart rate, and how much sweat the body loses. To measure mental sharpness, the nurses will complete a quick reaction-time test before and after the simulation. Their physical performance during the CPR scenarios will be analyzed by a computer system that measures the depth and rate of chest compressions. Finally, their overall clinical performance will be scored by observers who watch for specific, safety-critical behaviors, such as washing hands correctly, asking the right questions about medication, and communicating clearly.

This study is a protocol paper, meaning it outlines the plan for research that has not yet been completed. The researchers have not yet collected the final data or determined the specific results of how heat affects performance. Instead, this document details the rigorous method they will use to find the answers. By combining controlled environmental conditions with realistic clinical simulations, the study aims to provide clear evidence on the point at which heat begins to impair a nurse's ability to work safely. The findings are expected to help hospital administrators and policymakers decide when to turn on air conditioning or deploy fans, and at what temperatures these actions should be triggered. The ultimate goal is to protect the well-being of healthcare staff and, by extension, ensure that patients receive safe, high-quality care even during the hottest days of the year.