Short Answer 
Schools close when temperatures or wind chill fall below -20°F to protect health, following established safety guidelines. Health and safety standards align with workplace regulations, yet no legal maximum temperature exists for schools. Extreme conditions, like temperatures below -35°F for prolonged periods, prompt universities to consider operational changes for safety.
Step 1: Understand Temperature Guidelines
Schools determine whether to close based on specific temperature thresholds. When the air temperature or wind chill is below -20°F (20 degrees below zero), schools must close for safety reasons. This policy ensures that students and staff are not exposed to dangerous cold conditions that could jeopardize their health.
Step 2: Review Health and Safety Standards
Schools are required to follow the same health and safety regulations as workplaces, which include maintaining safe interior temperatures. While there is a recommended maximum temperature of 24°C from the World Health Organization, there is currently no legal limit for maximum working temperatures in educational settings.
Step 3: Recognize Extreme Cold Conditions
In extreme cold, such as when temperatures or windchill fall below -35¬∞F for more than three hours, universities like the University of Minnesota will assess if reduced operations are necessary. This means potential limitations on activities and attendance to ensure the safety of everyone on campus. It’s crucial for institutions to be proactive in monitoring weather conditions.