Hot showers create high humidity levels in bathrooms, often reaching 100% relative humidity, which can lead to mold growth and poor indoor air quality. Research from the Illinois Institute of Technology emphasizes that prolonged moisture encourages aggressive mold species, posing health risks. While extractor fans are commonly used in U.S. homes, studies indicate they may not be sufficient alone, as they often rely on limited airflow and may leave humidity levels above 80% after showers. In contrast, opening a window allows for natural ventilation, significantly reducing humidity levels to 65% in just 10-15 minutes. This method is particularly effective in humid climates, as demonstrated by research published in the PSEN journal of Prima Scientific. The Environmental Protection Agency supports maintaining dry indoor conditions to prevent health issues associated with mold. Ultimately, while extractor fans can be beneficial, combining them with open windows provides optimal air circulation and moisture control, highlighting that simple actions can have a significant impact on health and home maintenance.