As temperatures drop, office windows stay shut, heaters or HVAC systems switch to recirculation, and buildings that felt comfortable in summer can begin to feel oppressive. For a growing number of workers, this seasonal shift brings a familiar set of complaints like headaches, itchy eyes, dry throat, persistent fatigue, dizziness or difficulty concentrating. These clustered, building-related symptoms are commonly grouped as "sick building syndrome" (SBS), a syndrome not tied to a single disease but to the indoor environment itself.
Public-health bodies including the World Health Organization and occupational agencies warn that sick building syndrome becomes more frequent in colder months because ventilation is reduced, humidity falls, and heating systems redistribute indoor pollutants and biological agents. The result is not just discomfort. Poor indoor air quality reduces productivity, raises absenteeism and can aggravate asthma and other chronic conditions.
Why Sick Building Syndrome Increases In Winter
Windows stay closed, so ventilation falls
In winter people keep windows shut to stay warm. Many HVAC systems are set to recirculate indoor air to conserve energy. Reduced fresh-air exchange concentrates indoor pollutants (carbon dioxide, volatile organic compounds, cleaning-product vapours, and bio-aerosols), which is a primary driver of SBS. Agencies such as the US Environmental Protection Agency note that poorly ventilated buildings have higher occupant symptom reports.
Low humidity irritates mucous membranes
Heating and indoor recirculation commonly lower relative humidity. Dry air irritates nose and throat, impairs mucosal defenses against viruses/bacteria, and can increase perception of dryness and irritation, frequent SBS complaints. WHO and occupational-health reviews highlight humidity control as key to indoor comfort and health.
HVAC maintenance lapses redistribute contaminants
Winter is when heating elements, ducts and filters are used intensively. Poorly maintained filters, damp ducts or microbial growth in cooling/heating systems can release mould spores, endotoxins and other irritants into occupied spaces, triggering eye, nose and respiratory symptoms. The US NIOSH and ASHRAE stress regular maintenance and proper filtration.
Chemicals and cleaning agents accumulate
Indoor sources, off-gassing from furniture, paints, printers, cleaning agents and perfume, build up when air exchange is low. During winter, increased cleaning or use of disinfectants (for infection control) can add volatile organic compounds (VOCs) that cause headaches and irritation. Occupational guidance recommends low-VOC products and adequate ventilation during and after cleaning.
Higher co-exposure to biological agents
Colds and influenza circulate in winter. When ventilation is low, infectious aerosols linger longer and can co-exist with irritant pollutants, amplifying symptoms and absenteeism. Health agencies therefore recommend combined strategies of ventilation, masking (during outbreaks), and hygiene.
Practical Preventive And Management Steps For Workers And Employers
For employees:
- Raise concerns with facility management when you or many colleagues have similar symptoms. Ask about ventilation rates and maintenance schedules.
- Take short breaks outdoors when possible to refresh.
- Keep hydrated and use a small personal humidifier if air is dry (30-50% relative humidity is comfortable).
- Clean your workstation (keyboard, phone) to reduce local bio-load; avoid strong perfumes or sprays that add VOCs.
- If you have asthma or allergies, carry prescribed inhalers/medication and inform occupational health.
For employers and facilities teams:
- Increase fresh-air ventilation: Do this where feasible; balance energy needs with health. Use demand-control ventilation wisely (CO2 sensors can guide fresh-air flow).
- Maintain HVAC systems: Replace filters on schedule, inspect ducts, eliminate water intrusion and remediate mould promptly. Follow ASHRAE recommendations.
- Monitor indoor air: Simple CO2 monitors, and periodic PM2.5 and humidity checks, give actionable signals.
- Use appropriate filtration: MERV-rated or HEPA filtration for higher risk areas and during outbreaks.
- Adopt safer cleaning: Use low-VOC products, ventilate during/after cleaning, and avoid excessive fumigation.
- Encourage flexible work: Remote or staggered schedules reduce occupant density during high-risk periods.
When To Seek Medical Advice
If symptoms persist for days, recur only while at work, or if employees show respiratory exacerbations (wheezing, breathlessness), seek occupational health assessment. Documenting symptom patterns (improvement away from the building) helps identify environmental causes.
Sick building syndrome is not a mysterious malady, it is a predictable consequence of poor indoor environmental quality, and winter conditions (closed windows, recirculation, low humidity, and HVAC strain) make it worse. The good news is many drivers of SBS are fixable, like better ventilation, regular HVAC maintenance, humidity control, sensible product choices and employee engagement sharply reduce symptoms and improve wellbeing. Employers, building managers and workers need to treat indoor air as a key occupational-health condition, because healthy air is as essential to productivity and safety as any other workplace standard.
Disclaimer: This content, including advice, provides generic information only. It is in no way a substitute for a qualified medical opinion. Always consult a specialist or your doctor for more information. NDTV does not claim responsibility for this information.
