While most people try to avoid prolonged exposure to soaring temperatures, workers in some professions don’t have that option. Heat stress and strain is an underrated and dangerous occupational hazard, and a Mercer University professor hopes to help employers keep their staff safe on the job through a tool she is developing.
Dr. Annie Mulholland, assistant professor of kinesiology in the College of Health Professions, is piloting her Heat Strain Index this summer. She finished collecting survey results in July and has moved on to the data analysis stage.
“My broad research interests are in occupational health and safety, and I’m particularly interested in heat or heat stress as an occupational hazard, the physiological challenges that presents, and how to solve those physiological challenges while keeping people working,” she said. “The obvious answer is that people shouldn’t work in the heat when it gets too hot because then it’s dangerous, but there are a lot of jobs where that’s not an option because the world has to keep going.”
Outdoor workers in industries such as emergency response, disaster recovery, construction, landscaping, agriculture and entertainment face an increased risk of heat strain. However, it’s also a concern in many indoor workplaces, including warehouses, factories, transportation and trucking, and jobs that require the use of personal protective equipment, Dr. Mulholland said.
Heat exposure is hard to measure and quantify over time. In addition to temperature and humidity, individual characteristics such as hydration, fitness level, sleep duration and amount of equipment being worn contribute to how each person responds to heat over time. Chronic dehydration and heat exposure can lead to conditions like cardiovascular disease and kidney disease, Dr. Mulholland said.
While effective cooling methods and technologies have been created in the lab to address heat stress, they are often expensive and difficult to implement in the real world. Dr. Mulholland was interested in creating a more practical intervention.
Inspired by a survey from an Iranian research group, she first began developing the Heat Survey Index with professor Dr. Jonathan Wingo as a Ph.D. student at the University of Alabama.
The survey, which currently contains 20 questions about how a person feels after working in heated conditions, was completed by 170 people across the country in relevant industries this summer. Now, Dr. Mulholland is analyzing that data and will refine and condense the question list to 10 or fewer.
The second phase of the project will involve surveying respondents using the revised question list. As an additional component, the respondents’ core temperature and heart rate will also be measured, which will gauge how hot their body is getting and how hard they are working.
“The end goal is to create a short-form survey, almost like an exit survey, that could be used to individualize recovery or manage (a person’s) risk at work the next day,” Dr. Mulholland said. “You got really hot today. We know that heat stress can compound over multiple days, so maybe tomorrow you take it easy. Or the opposite. We might actually be able to tell you that it’s safe for you to continue working.”
As another example, the Heat Strain Index results might show that a person needs to drink more water after work to ensure they are properly hydrated before their next shift.
The tool could be provided for free and the survey completed on paper or anonymously, making the burden low and eliminating barriers that might exist for other interventions.
“It could be used in workplaces as a running measure of heat stress,” Dr. Mulholland said. “Having something that is very low cost, noninvasive would allow us to track heat stress and strain over time. Hopefully, it would be really beneficial to both employers and employees in keeping everybody safe and keeping everybody working.”
