After weeks of triple-digit temperatures across Texas, many people have felt firsthand how differently the body can respond to heat and continue performing at a high level, while others experience dangerous heat stress under the same conditions.

Dr. Steven Riechman of the Department of Kinesiology and Sport Management at Texas A&M University is looking to understand why. Through the Southern Heat Initiative, he is leading a growing network of researchers in Texas and beyond to characterize individual differences in how people respond and adapt to hot environments.

“Most of what we know about thermoregulation, or how we handle heat, comes from cool climates like Pennsylvania, Connecticut and Massachusetts,” Riechman said. “Understanding how people in the southern U.S. respond to heat can expand what we know about thermoregulation.”

Decades of thermoregulation research have established heat-safety practices largely based on populations with limited heat adaptation. In southern regions, however, greater heat adaptation may allow individuals to safely tolerate temperatures that would warrant restrictions for similarly healthy people from cooler climates. Recognizing these differences could improve heat-safety guidance while avoiding unnecessary restrictions on work and activity. Despite living in a hot climate, a Texan who spends most of the summer moving between air-conditioned buildings and cars may have little heat exposure. However, a roofer or farmworker in the same region can spend long hours outside each day tending to demanding tasks. Riechman and his team explore these differences to see how ongoing heat exposure affects the body.

The Southern Heat Initiative includes 8 institutions including University of Arkansas, Tarleton State University, Baylor University, Texas Tech University, and the list is growing. These institutions across Texas and other regions had to meet specific annual heat index criteria to be included. “Developing shared research protocols across multiple institutions allows us to assess populations with different environmental, occupational and demographic backgrounds,” Riechman adds. “It helps us build the large datasets needed to understand individual variability and develop predictive models for heat response.”

At the Tactical Performance & Thermoregulation Laboratory, Riechman is examining proteins and metabolites found in blood, urine, saliva and sweat to identify changes that occur in the body. “Heat exposure increases heat shock protein 70, which helps protect cells,” Riechman notes. “Metabolites can change more quickly and provide a signal of how the body is responding to heat in the moment.”

Riechman sees potential in wearable technology that could eventually track some of those biomarkers through sweat and gather measurements such as heart rate, activity and body temperature. “A device similar to a fitness watch or ring could make it possible to track those changes over time without relying on repeated laboratory testing,” Riechman shared.

The next step is determining how prepared someone is for heat and when conditions can become dangerous. AI and machine learning can analyze a person’s heat exposure with physiological and biological measurements to notice patterns in larger populations. This builds the foundation for a thermal digital twin, a digital representation of an individual’s ability to regulate body temperature that updates as new data is collected.

“The long-term goal is to predict a person’s heat tolerance, adaptation and risk before conditions lead to dangerous outcomes, such as exertional heat stroke,” Riechman said. He hopes to develop technology that can recognize warning signs in a person’s physiological response and alert them before a heat-related incident. The technology may support first responders, military personnel, farmworkers, construction workers, athletes and others who are regularly exposed to high temperatures.

As the Southern Heat Initiative continues, Riechman is advancing heat safety beyond general guidelines toward predicting how each person will respond to extreme conditions. “On the hottest days, knowing that difference before the body reaches its limit can change how people prepare, perform and respond,” he emphasized.

For media inquiries, contact Ruben Hidalgo.