The article discusses elevated ambient temperatures in the workplace, which can have a negative impact on humans. This is a hot microclimate, which is defined by Wet Bulb Globe Temperature norms and standards. Despite the Health and Safety regulations in force in Poland and recommendations regarding air conditioning, ventilation and access to drinks, in many industries—including metallurgy, construction and agriculture—the risk of overheating remains high and the problem remains unresolved. The aim of the study was to design and preliminarily evaluate an innovative textronic cooling module intended to reduce heat stress in work clothing. A heat exchange model was developed for three levels of physical exertion (light, moderate, intense), taking into account skin temperature, ambient temperature (WBGT), and the heat exchange mechanisms of the worker's body. The model was verified in laboratory tests conducted under conditions similar to real-life conditions on a human skin model. The results obtained confirmed that the use of the cooling module leads to a significant reduction in temperature in the undergarment area and a reduction in the heat load on the worker's body. A cooling power exceeding 220 W/m² proved sufficient to effectively reduce heat stress, even during intense physical exertion >300 W/m² energy expenditure. The high correlation between the model results and measurements, with a 9% coefficient of variation between measured and modelled values, confirmed the effectiveness of the proposed solution and the correctness of the computational assumptions. The developed module has great implementation potential in industries with elevated workplace temperatures, where employees are exposed to overheating. This contributes to the development of new textronic protective clothing that increases work safety. Further research is recommended, focusing on optimizing the module's design and evaluating its effectiveness in real-world conditions, taking into account ergonomics and user comfort.