Why Are Hospitals Cold?

You go to visit your family member in the hospital or you yourself are being wheeled into the operating room for a procedure and your first thought is “Burr!! Is it just me or is it cold in here?!” Don’t worry you are not alone in thinking this. Actually, this seems to be a common question asked by healthcare staff, patients, and patients’ family members when walking into the hospital. This one initial question then begs a multitude of other questions such as, why are hospitals so cold? What is the standard hospital room temperature? Is the air conditioning in hospitals always on? Is there a scientific or medical reason to keep cooler temperatures in the hospital? Let’s look into these questions about hospital temperature in more detail.

Why Are Hospitals Cold

Microorganism Growth

First let’s talk about microorganisms and the basics of how they grow. Overall, microorganisms can grow at a wide variety of temperatures, with some microorganisms even being on the extreme ends of hot and cold. However, all microorganisms have an optimum temperature for growth.  In general, microorganisms tend to grow slower when there is a lower temperature, meaning bacteria in cold temperatures tend to grow at a much slower rate than if bacteria were in a warm environment. There are of course other factors impacting the growth of microorganisms too such as the pH, and most of it tend to grow best when in more of a neutral environment. 

Hospital Temperature Standards

Research has shown that the temperature within the hospital can vary depending on the type of unit one is working on. For instance, on a general hospital ward the temperature of patient rooms, the nursing station, or simply a day room can range from 75.2°F to 80.6°F. In outpatient departments, the waiting room and consult rooms tend to be a little on the warmer side at 78.8°F to 80.6°F. The emergency department and standard operating room temperature can sometimes be slightly cooler with a low temperature of 73.4°F. Season can also impact these temperatures with summer months allowing for a little warmer room temperatures when compared to winter months. 

Why Are Hospitals Cold?

Many people often ask if there is a reason to explain why hospitals are kept at these predetermined levels. The answer to this is yes. Over the years, research has been conducted to determine what is the healthiest, most appropriate, and acceptable range of temperatures for various medical settings. As previously mentioned, depending on the type of bacteria the optimum temperature for growth can vary, but usually, bacteria and diseases are most likely to grow in overly-warm environments. Likewise, bacteria can spread more rapidly when they are in a room with improper ventilation. Therefore, careful monitoring of the climate in hospital rooms and doctors’ offices and ensuring appropriate ventilation is crucial and allows for the potential reduction in bacteria growth.

Why Are Operating Rooms Cold? 

Operating rooms are one particular set of rooms that naturally always feel a bit cooler. Is there a reason for this? Again, the answer is yes. In addition to the reasons provided previously regarding microorganism growth, operating rooms are also often cooler due to comfort. Depending on the procedure being performed, some can become quite lengthy. When taking this into consideration along with the fact that the healthcare team has to wear a significant amount of personal protective equipment (PPE) from gowns, to face masks and shields, to gloves, and then stand under bright, hot lights it makes sense that the rooms are cooler. These team members need to be as comfortable as possible to complete their jobs well. We would not want them to be so overheated that it becomes difficult for them to complete their tasks well.

Humidity in the Hospital

Another important factor in minimizing bacteria growth and infections is relative humidity. Allow it may seem surprising to some, drier air allows microbes and infectious agents to travel further and longer. Dry air also lowers the body’s natural immune defenses that normally would protect us from getting sick and contracting infections. Studies have shown that steam humidification can significantly reduce the spread of diseases that are transmitted through the air or by way of contaminated surfaces as a secondary route, such as influenza. With this in mind, it then makes sense that hospital rooms monitor the humidity level closely and maintain a certain level. 

What is that optimum level though? According to the US Environmental Protection Agency the ideal indoor relative humidity level is between 30 and 60%. Operating room humidity, as well as humidity in most hospital rooms typically ranges around 50-60%. This allows for the best environment in terms of being able to minimize the spread of potential infectious agents through the air and on surfaces. It has been noted that maintaining predetermined relative humidity levels in operating rooms has been essential in controlling the growth of microorganisms and preventing electrostatic discharge. In addition, the humidity level can affect the shelf life of sterile products and supplies used during surgery. By keeping the predetermined humidity level, the shelf-life for supplies can be maximized.

Hospital Air Conditioning

The air conditioning within a hospital setting is vital. Ensuring proper ventilation further helps to decrease the spread of infections. A hospital’s HVAC system is able to help reduce the density of particles within the air by introducing new, clean air. This helps to decrease the number of bacteria or viruses that may be found in larger air particles. The hospital HVAC system also allows the movement of dirty air out of the hospital in a logical pathway that allows for the cleanest air to first be introduced to the most sensitive areas such as operating rooms. The air then gradually is moved by pressure differences to less clean areas and eventually out of the hospital.

Final Thoughts

As you can see there is a lot that determines how warm or cool a hospital keeps its temperature and it can vary depending on the type of unit you are on. It is important to understand the many factors that go into choosing the temperature and that choosing a temperature is scientifically driven. Although it may seem cool inside many hospitals there are hospital temperature regulations and these are in place to decrease the likelihood of patients or family members and visitors from contracting diseases unnecessarily. 

Written by
Tabitha Cumpian