Monitoring and Controlling Temperature and Humidity in Hospitals

Hospitals are where we go to get better when we’re sick. However, that means that there must be strict parameters in place to make sure that viruses and bacteria don’t spread and make other people sick. Monitoring and controlling both temperature and relative humidity is key in helping reduce infectious disease transmission from aerosol or airborne infection. To find out more about monitoring requirements for temperature and humidity you can visit The Joint Commission’s standards page.

Environmental exposure is a common hazard for viruses, bacteria and even fungi as they attempt to travel between hosts. Factors such as temperature, humidity (both relative and absolute), sunlight (ultraviolet light) exposure, and even atmospheric pollutants can all act to deactivate free-floating, airborne infectious organisms.

Temperature is actually one of the most important factors affecting virus survival, as it can affect the state of viral proteins and the virus genome. Virus survival decreases progressively at 20.5°C –24°C then < 30°C temperatures. This relationship with temperature is held throughout the humidity range of 23%rh- 81%rh.

The recommended room temperature for hospitals during the summer ranges from 23°C-27°C in the emergency room, including in-patient and out-patient areas, as well as X-ray and treatment rooms and offices. In winter, the recommended temperature is slightly lower, ranging from 20°C in some in-patient and out-patient areas, as well as offices, and up to 24°C -26°C in in-patient and out-patient areas. The recommended relative humidity (RH) is fairly constant throughout the hospital, between 50-60%rh.

The recommendations for newborn baby and hydrotherapy treatment rooms are higher at 27°C –28°C. Again, the corresponding recommended range of RH is fairly constant, but slightly lower, ranging from 40%rh -50%rh, but up to 55%rh–60%rh for more critical areas, such as operating theatres and recovery, the intensive care unit and childbirth/delivery suites.

If temperature is so important, then why do we need to measure relative humidity? The range of relative humidity varies depending on what organism we are targeting. The survival of viruses depends partially on levels of RH. For example, at a temperature of 21°C, influenza survival is lowest at a mid-range 40%rh–60%rh. For bacteria, the effect of carbon monoxide (CO), enhances the death rate at less than 25%rh, but protects the bacteria at higher RH ~ 90%rh.

Different airborne infectious agents have differing conditions under which they are optimally suppressed. Within a hospital, there needs to be a decision on which airborne pathogen poses the most risk to patients and staff. Once that is established you can put in the best protective measures, such as Guardian. Guardian provides 24/7 wireless monitoring at the touch of a button and can easily scale, adapt and meet the needs of any facility environment. Contact us to find out more.