ST. PAUL — Findings from a collaborative research project by the Minnesota and Wisconsin Departments of Health are challenging previously held notions regarding heat-related illnesses — and who is most at risk for them.

Researchers from both states teamed up to analyze data from emergency room visits for heat-related illnesses such as heat exhaustion, heat rash, heat cramps and heat stroke from 2006-2015.

Most messaging surrounding heat-related illness stresses the risk posed toward the very old and very young. But Tess Konen, an epidemiologist at the Minnesota Health Department and a lead researcher on the project, said they found that the population most likely to make an emergency department visit for a heat-related illness is actually teens and adults between the ages of 15 and 34.

The project didn’t reveal why, but Konen said this population’s increased risk is likely due to increased heat exposure from athletics or outdoor work.

“We also found that males are twice as likely to go to the emergency department for heat-related illness than women, and again this is probably related to outdoor work but our data doesn’t include the ‘why,’” she said.

The project’s finding that teenagers and adults are more susceptible to heat-related illness than previously thought might call for increased safety precautions for strenuous outdoor activities this population engages in during the summer, like construction work and summer athletics training.

Dr. Brad Reeves is the director of sports medicine at Sanford Health and team physician for the University of South Dakota, South Dakota State University, University of Sioux Falls and Sioux Falls Skyforce. At Sanford Health, his team also advises high school athletic directors on best health practices for athletes.

To keep athletes safe during summer training, Reeves said coaches should advise them to stay hydrated, avoid caffeinated beverages, eat healthy foods and dress in loose-fitting, light-colored clothing.

“We work with coaching staffs to have practice going more into the cooler periods of the morning or evenings and giving different breaks,” Reeves said. “And sometimes, in the heat of the day, just spending a limited amount of time outside.”

Dr. Autumn Nelson of Sanford Health said it's best to avoid being outside from 2 to 4 p.m. during the summer months, because this is when the heat and sun are the most intense.

Symptoms of heat exhaustion can include heavy sweating, faintness, dizziness, fatigue, high heart rate and low blood pressure, according to Nelson.

"We like you to see a doctor if your symptoms don’t improve within an hour of having an increased heart rate, low blood pressure, if your temperature increases over 102 degrees, you get confused or are unable to drink water," Nelson said.

Another surprising finding from the study is that rural populations have a higher risk of emergency room visits for heat-related illnesses than urban populations.

In the past, Konen said, medical researchers have focused on the risk of heat-related illness in urban areas because they are more at risk for urban heat island effect, a phenomenon that occurs when concrete and asphalt absorb heat and slowly release it throughout the day, increasing the temperature in cities.

For individuals who don’t have air conditioning in their homes, Konen recommends seeking out public cooling centers in urban areas during the day.

“But that might be a little more of a challenge in rural areas where things are a little bit further apart for people to be able to reach those prevention areas,” she said.

The project’s analysis also found connections with heat-related illness and lower socioeconomic status.

“That could be another piece of the puzzle of what’s driving some of those higher rural rates [of heat-related illness] – higher poverty.”

Minnesota and Wisconsin have similar populations, weather and geography, making a collaboration between the two a natural fit, Konen said.

“I think the greater Minnesota piece and collaboration across the states is an important part of the project and something that I hope becomes more common with health for state departments to work together on issues that are cross-border issues,” she said.