Hot Days, High Stakes: Heat Illness and HR’s Role

As summer settles in and temperatures soar, HR leaders are on the front lines of protecting their workforce. Whether your teams are building homes, packaging goods or cooking meals, heat stress is a serious and growing health hazard — and increasingly, a compliance risk. 

In 2023, the U.S. Centers of Disease Control recorded over 2,300 heat-related deaths — the highest in nearly 50 years. Among them, 55 fatalities were job-related, making environmental heat exposure one of the deadliest workplace hazards. And the risk isn’t limited to outdoor jobs, like construction or landscaping. A 2025 survey by Harvard’s Shift Project found that 65% of indoor food service and retail workers reported feeling overheated at work, often in stockrooms, kitchens or buildings with poor ventilation. 

Employer Accountability Is Heating Up 

Regulators, insurers and courts are making it clear: the burden of heat safety is firmly on employers. They expect proactive measures — not just policies on paper, but meaningful actions like training, supervision and planning. 

Employer accountability rises with temperatures. Regulators and insurers expect more than good intentions — they expect real action, and heat illness prevention training is a vital first step. 

Failing to act doesn’t just increase injury risk — it opens the door to costly workers’ compensation claims, OSHA violations and legal liability.  

Know the Law: State Mandates & Federal Focus 

Several states now enforce specific rules on heat illness prevention. California, for example, requires formal heat safety programs for both indoor and outdoor workers. Oregon mandates shaded rest breaks and emergency procedures once temperatures reach 80°F, while Nevada has established protocols for acclimatization, with exemptions for small, climate-controlled employers. 

And it’s not just about state law. Warehouse and distribution center operators are already under the microscope, as OSHA and state agencies prioritize inspections in these high-risk environments during summer months. Being caught unprepared can result in preventable worker harm — and expensive citations. 

Who’s Most at Risk? 

It’s important to look beyond construction. Manufacturing teams, delivery drivers, warehouse and fulfillment staff, kitchen and food truck crews, cleaning services and healthcare workers in non-air-conditioned facilities are all vulnerable. Even employees in office settings — particularly in older buildings with poor ventilation — can experience heat stress during extreme weather. 

According to OSHA data, nearly half of heat-related illnesses occur on a worker’s very first day, and 80% happen within the first four days. In nearly all these cases, employees had not received training on acclimatization — the process of allowing the body to gradually adjust to working in heat. Additionally, more than half of supervisors had received no prevention training at all. 

These findings underscore the need for onboarding protocols that do more than introduce safety policies. New and returning employees need time to build up heat tolerance, ideally through phased work schedules and close supervision during the first week. 

Recognizing the Warning Signs 

Heat illness can escalate fast. Early symptoms include: 

• Dizziness 
• Nausea 
• Headache 
• Confusion 
• Heavy sweating 

In more severe cases, workers may stop sweating altogether, develop muscle cramps, or become disoriented. Supervisors and peers must be trained to recognize these signs early and respond immediately. 

What Prevention Looks Like in Practice 

An effective heat illness prevention program blends common-sense practices with clear policies and effective training. Employees should have access to cool, clean drinking water and shaded or ventilated break areas. Workloads should be adjusted based on temperature and exertion levels. Managers should monitor new employees closely and encourage a culture where speaking up about discomfort is supported. 

Acclimatization plans are essential — not optional — and training should address both the science of heat illness and the human reality of working through it. Above all, the organization must treat heat safety as a core component of workplace wellbeing, not an afterthought tied to compliance. 

Don’t wait for the thermometer — or a regulator — to force action. Training must be provided before the start of high-heat work — ideally in the weeks leading up to summer. Waiting until heatwaves hit can put unprepared employees at unnecessary risk. By building strong, informed safety practices, HR professionals can reduce legal exposure, improve retention, and reinforce a workplace environment where employees feel valued and protected.