Winter conditions alter how respiratory viruses, such as influenza and common cold viruses, spread within buildings. Cleaning practices, products, and decision-making must adapt accordingly. Strengthening infection prevention and maintaining indoor environmental health requires winter-specific cleaning shifts as people spend more time indoors with reduced ventilation and longer viral persistence on surfaces in colder, drier air.
In the United States, flu season typically starts in the fall and extends through winter. While influenza viruses spread year-round, we see many more people get sick from October through May. Unfortunately, many cleaning programs remain unchanged throughout the year. A “one-size-fits-all” program that doesn’t account for seasonal shifts increases the risk for infectious disease transmission.
Adapting a cleaning strategy
Respiratory viruses spread through close interactions among people, contact with contaminated surfaces and hands, and airborne transmission. Cold, dry air allows viruses to persist, travel further, and remain viable on surfaces for longer periods.
Cleaning for health in winter is not simply about cleaning more often. It is about cleaning differently and using science to guide changes in products, practices, processes, and decision-making across the entire cleaning chain. When facility managers treat winter cleaning as a targeted public health intervention rather than routine maintenance, buildings can play a measurable role in reducing viral transmission and protecting both occupants and front-line workers.
Winter brings operational challenges. Facilities often reduce fresh air intake to conserve energy. Cleaning staff usually face increased workloads due to prolonged indoor occupancy, illness among building occupants, or weather disruptions. Colder temperatures often affect chemical application and performance. To meet these challenges, facility managers must intentionally design winter cleaning programs and demand a focus on health outcomes.
Shifting from appearance to health
A surface that appears clean can still harbor infectious viruses capable of spreading illness. Shifting from cleaning for appearance to cleaning for health requires coordination across the chain so that products, protocols, training, and expectations are aligned with infection prevention goals. Winter cleaning programs should prioritize:
- High-touch, high-occupancy surfaces, such as hotel lobbies, handrails, restrooms, and common equipment.
- Frequency and timing based on risk patterns, not arbitrary schedules.
- Measured effectiveness, not assumptions of cleanliness.
Selecting products
The choice of cleaning and disinfecting chemistry becomes more critical in winter when seasonal respiratory viral loads and occupancy patterns shift. Facility managers and building service contractors need to ensure the products they choose:
- Are supported by evidence demonstrating efficacy against enveloped viruses, such as influenza, in real-world conditions.
- Include clear, science-based instructions on dwell time, dilution, and application methods.
- Remain stable and effective when stored or applied in cooler environments.
- Balance antimicrobial performance with worker and occupant safety.
Facilities and cleaning companies must not overuse more potent chemicals in winter without understanding exposure risks. Stronger chemicals do not necessarily equate better performance. Effective winter cleaning is about using the right chemistry correctly, especially when increased frequency is needed.
Rethinking processes
To interrupt viral transmission, cleaning staff must redesign processes to reflect actual human behavior and occupancy during winter. This includes rethinking where, when, and how often cleaning occurs.• Use a floor plan to map and analyze occupant movement to target high-risk areas.
- Increase cleaning frequency for identified high-touch surfaces.
- Build cleaning schedules based on activity patterns rather than time schedules alone.
- Separate cleaning and disinfection tasks, ensuring teams apply disinfectants to already clean surfaces for maximum effectiveness.
Choosing consistency over speed
In winter, consistency becomes more important than speed. Disinfectants require a specific dwell or contact time—the period a surface must remain wet with the disinfectant—to work. Yet, rushed
application is one of the most common failures in real-world cleaning.
To ensure proper disinfectant application, cleaning teams should reinforce the use of:
- Application tools that support even coverage rather than over-spraying.
- Verification tools, such as fluorescent markers and adenosine triphosphate (ATP) testing, to confirm cleaning quality.
- Routine verification processes that confirm tools (microfiber cloths and mops, dispensers, dilutors) are clean and functioning correctly.
Mechanization and automation, such as touch-free dispensing systems, can improve consistency while reducing cross-contamination risks when implemented correctly.
Protecting the workforce
Cleaning staff face higher workloads and increased exposure to pathogens during winter.
Facility managers must adapt training to explain:
- Why cleaning practices need to change in winter
- Why cleaning staff must take on the role of infection prevention professionals.
- When the use of personal protective equipment (PPE) is required.
- How to recognize symptoms of respiratory illness.
Protecting cleaning workers is inseparable from protecting building occupants. A workforce that feels informed, valued, and protected is more likely to deliver consistent, high-quality cleaning outcomes.
Enhancing indoor air quality
Beyond surfaces, the air we breathe plays a significant role in respiratory virus transmission. According to the Environmental Protection Agency, no single air strategy is sufficient on its own. Effective prevention depends on a multi-layered approach that complements surface cleaning and hygiene practices.
- Increase outside air ventilation to the maximum extent practical to help dilute the concentration of virus-laden aerosols in indoor spaces.
- Adjust airflow patterns to avoid direct air movement between people and exhaust air from smaller spaces like restrooms.
- Filter recirculated air through high-efficiency filters, such as MERV-13 or the highest MERV rating a building’s ventilation system can accommodate, to remove airborne particles.
- Place portable air cleaners in areas that are hard to ventilate with outside air or that have high occupancy.
- Utilize upper-room ultraviolet germicidal irradiation (UVGI) to reduce airborne virus transmission further. While not a replacement for ventilation or filtration, UVGI can be an effective supplement in high-risk areas.
- Set ventilation and filtration goals. The Centers for Disease Control and Prevention recommends five air changes per hour when using outdoor air ventilation alone or five equivalent air changes per hour when using a
combination of ventilation from outdoor air, filtration, and other air treatment.
Cleaning for public health
Flu and cold season is predictable. Cleaning programs that remain static during winter miss a critical opportunity to reduce risk, protect people, and demonstrate the actual value of professional cleaning.
When all sectors of the cleaning industry work together with a shared understanding of winter risk, cleaning becomes more than a service—it becomes a front-line public-health defense.
