Heat risks: Your workers may be more vulnerable than you think 

Climate Week NYC is a global event that brings together leaders from business, politics, healthcare, science, and civil society with the goal of initiating bold action. As a sponsor of the National Commission on Climate and Workforce Health, Mercer hosted two closed-door sessions called Learning Labs, designed to allow employers and various experts to share information, concerns, and progress in this area — and even some frustrations about the lack of progress.

One session focused on the impact of extreme heat on workers and business. Of all types of extreme weather events — hurricanes, flooding, wildfires, tornadoes — heat is the deadliest. From a business perspective, heat-induced lost labor productivity costs the US an estimated $100 billion annually, a figure projected to double to $200 billion by 2030. Over 69 million workers face hazardous heat on the job, particularly those in high-risk industries like construction, transportation, agriculture, and warehousing. But even when workers are not exposed to extreme heat at work, they may be at risk outside of working hours.

Just about everyone in the room had a personal story about how extreme heat has affected them — from restricted outdoor activities to decisions about where to live and which organization to work for. As business leaders, they discussed how the impact of extreme heat shows up in work-related injuries, productivity losses, increased absenteeism, healthcare claims, and mental health concerns, to name a few. Making a case for action starts with sizing the problem, so let’s begin with that.

The dangerous trajectory of heat-related health risks

Heat-related deaths in the U.S. have risen significantly over the past two decades, from 1,069 in 1999 to 2,325 in 2023, a 117% increase over that period. Heat-related deaths are understood to be under-reported because the primary cause of death that is typically recorded is the actual health event — for example, stroke — rather than heat.

Temperatures do not necessarily have to be all that high for people to be at risk. The National Weather Service classifies dangerous heat conditions — based on humidity as well as temperature — into four risk levels and outlines health hazards for each. 

OSHA cautions that severe heat-related illnesses can occur at lower heat indices and recommends employers monitor environmental heat. An on-site wet bulb globe temperature meter is the most accurate heat stress measurement tool, accounting not only for temperature and humidity, but also wind speed and solar radiation.

Of course, a person’s physical condition also plays a role in how they handle heat. It’s important to know that over 70% of heat-related work injuries and deaths occur during a worker's first week on the job, before they’ve had time to build tolerance to heat. Employers should ensure that new workers are allowed to have slow and gradual exposure to hot work environments.

Social factors

Nearly one-quarter of the US population is socially vulnerable to extreme heat exposure, according to the Census Bureau's Community Resilience Estimates for Heat, which takes into account such factors as housing quality, access to transportation, and financial hardship. Overall in the US, about 30% of homes lack central air conditioning; 20% have window units and about 10% have no cooling at all. Air conditioning is less common in the traditionally cooler parts of the country, such as the West Coast. This is becoming a serious problem as temperatures rise dramatically: at least 60 people died from a heat wave in Portland, OR last year.

Even if your workers have some type of air conditioning, they may have difficulty paying for it. Almost a third of Americans say they struggle to pay their electric bill, and that number jumps to 49% for those making less than $50,000 per year. Overall, 5% of households say they were unable to use air conditioning in the past year because their equipment broke and they couldn’t afford to replace it, or their equipment was shut off because they were unable to pay their bills.

What you can do – and some resources that can help

As we heard during the Learning Lab, some employers are already taking safety measures to protect outdoor workers from heat such as providing hydration and cooling breaks, protective clothing, and modified working hours to avoid hottest time of day. Health plans are making efforts to communicate directly with those at risk, providing tips and offering individualized support. Interestingly, within some state Medicaid programs, the health plan helps members at risk pay their electric bill to keep their air conditioners working. This is not something we have seen on the commercial side, but it could be worth exploring with your health plan – or within your own benefits department.  In fact, this might be a good time to look across all existing benefits and programs with a climate lens.

Here are some resources designed specifically for employers that can help you learn how to protect and support workers during extreme heat:

• A quick and easy resource is The National Commission on Climate and Workforce Health tip sheets for employers and workers.
• To learn where extreme heat is a threat to your population — and it’s often not where you might expect — you can load the ZIP code and headcount for your top four locations in our Climate Health Forecaster. The model identifies the top climate peril in each location and estimates the impact of extreme weather on your medical claims over the next ten years.
• The Climate and Worker Health Scorecard can help you assess your organization’s current ability to mitigate health risks stemming from extreme weather – and discover opportunities to do more. Ideally someone from Benefits and someone from Risk Management complete the scorecard together. If these teams do not already work together on this topic, it is a great way to start.

You will also want to keep an eye on the regulatory environment. OSHA has been working on a workplace heat standard, but its future is uncertain. At the state level, seven states — California, Colorado, Maryland, Minnesota, Nevada, Oregon, and Washington — have established heat-protection standards for some or all workers. These rules vary in their scope and effectiveness. Some states, including Texas and Florida, have passed laws that block local governments from implementing their own heat-protection ordinances.

We heard loud and clear that businesses need guidelines that are both effective and financially viable. There are several examples of state and local entities that have used financial incentives to successfully drive heat-protection efforts. Those examples provide models that could be applied and adopted more broadly.

One clear takeaway from Climate Week is that real opportunities exist for businesses to think more creatively about how to better protect their workers and their families from heat risk. Mercer wants to help keep the momentum building.

Mercer is a presenting sponsor, and Susan Potter is the co-chair, of the National Commission on Climate and Workforce Health. Click to learn more about the Commission and the work we’re doing to help employers address the risk of extreme climate on employee health and business performance.