When working on hot days, it's crucial to understand and mitigate the risks of heat-related illnesses. Here's a breakdown of key safety measures:

1. Training and Education: Employers must ensure employees are trained on the hazards of heat exposure, prevention of heat-related illnesses, recognizing dehydration symptoms, and emergency response 1, 11. This includes understanding environmental and personal risk factors, such as the burden of clothing and PPE [1]. Training should be readily understood and allow for employee feedback [1].

2. Acclimatization: Implement a written acclimatization plan, especially for new employees or those returning from extended absences 11, 13. This plan should address acclimated and unacclimated workers, the effects of clothing and PPE, personal and environmental risk factors, and the use of auxiliary cooling systems [2].

3. Access to Shade: Provide shade areas that are immediately available when the heat index equals or exceeds 80 degrees Fahrenheit [3]. These areas should be open to outside air or mechanically ventilated [3], and large enough to accommodate employees during rest periods 4, 5. If providing shade is unsafe or interferes with work, alternative cooling measures like cooling vests or water-dampened clothing must be implemented [4].

4. Drinking Water: Ensure a sufficient supply of cool or cold drinking water is readily available at no cost when the heat index reaches 80 degrees Fahrenheit or higher [4]. Employees should have the opportunity to drink up to 32 ounces per hour 1, 4. Electrolyte-replenishing beverages can supplement, but not replace, water supplies [4].

5. High-Heat Practices: When the heat index exceeds 90 degrees Fahrenheit, implement high-heat practices, which may include engineering and administrative controls [4].

6. Communication and Monitoring: Establish communication systems so employees can contact a supervisor when needed [5]. Implement methods to promptly identify employees showing signs of heat-related illness, such as regular communication or a buddy system [5].

7. Emergency Response: Designate employees authorized to call for emergency medical services and ensure emergency medical care is immediately available 12, 13. The Emergency Medical Plan must address employee exposure to excessive heat [2].

8. Workload Management: Be aware of workers' activity levels, classifying workload as light, moderate, heavy, or very heavy, to prevent a hazardous combination of environmental and metabolic heat [6].

9. Thermal Conditions: Employers should measure and record thermal conditions frequently [7].

10. Additional Considerations: Be mindful of nonoccupational factors like drugs, alcohol, and obesity that can affect heat tolerance [8]. Also, consider the effect of direct sunlight when developing acclimatization plans [2].