OSHA Heat Expectations Intensify Across Wisconsin and Illinois 

Extreme heat conditions are impacting both Wisconsin and Illinois this week, with widespread Extreme Heat Warnings and elevated heat risk levels. Employers should anticipate heightened enforcement under the Occupational Safety and Health Administration (OSHA) Heat National Emphasis Program (NEP).  While the rest of the country has already experienced extreme heat, employees in Wisconsin and Illinois are not acclimated to these temperatures, especially newer workers who have not yet learned how to work efficiently, how much water to drink, how to dress, and are trying to prove themselves by working hard.  They may fail to pace themselves. Extra care is necessary from leadership in terms of giving direction about what to do, and what not to do this week.   

Wisconsin:

• Extreme Heat Warnings in many areas including Madison, Milwaukee, and Waukesha
• Heat index values generally ranging from 95–110°F+

Illinois:

• Widespread dangerous heat conditions including Chicago and downstate regions
• Heat index values frequently exceeding 100°F

• Red (Major Risk): Impacts most workers without cooling, hydration, or protective controls
• Magenta (Extreme Risk): Dangerous, prolonged heat with limited overnight relief affecting all workers without controls

A proposed OSHA Heat Standard is being finalized, but is not yet on the books. However, OSHA continues to enforce heat hazards under the General Duty Clause. Inspection expectations are already aligned with the forthcoming federal heat standard:

• Documented heat illness prevention program
• Real-time monitoring using heat index or Wet Bulb Globe Temperature (WBGT) OSHA Technical Manual (OTM) - Section III: Chapter 4 | Occupational Safety and Health Administration 
• Demonstrated use of controls in the field 
• Training and defined emergency response procedures 

1. Acclimatization 

• Gradually increase workload for new and returning workers 
• Closely supervise during early exposure periods 
• Document schedules and supervisory oversight 

2. Water 

• Provide cool, potable drinking water at all times 
• Encourage frequent consumption 
• Ensure water is staged close to work areas 

3. Rest 

• Implement scheduled breaks tied to heat conditions 
• Increase frequency during peak heat periods 
• Use task rotation to reduce exposure 

4. Shade / Cooling 

• Provide shaded or cooled rest areas 
• Ensure proximity to active work zones
• Use fans, misters, or cooled trailers where feasible 

• Treat current conditions as high-risk under OSHA enforcement priorities 
• Align operations with Water–Rest–Shade–Acclimatization controls 
• Expect inspections during Extreme Heat Warnings in both Wisconsin and Illinois 
• Train supervisors to intervene proactively, not reactively 
• Document all actions as proof of compliance 

Employers in Wisconsin and Illinois are operating in major to extreme heat risk conditions. OSHA expects real-time implementation and documentation of protective measures. Failure to act increases enforcement and litigation risk.  Penalties can be high and create negative publicity about your organization.  How OSHA’s New Heat Rule Impacts Employers | EHS Today