This article challenges the generalized view of heat-related child mortality by demonstrating that heat exposure affects children under five differently across seasons and African regions. Using the Wet Bulb Globe Temperature (WBGT) index—a comprehensive metric including temperature, humidity, wind, and solar radiation—the study analyzed mortality data from Health and Demographic Surveillance Sites in 13 countries. Unlike most research that averages effects across countries and seasons, this study highlights that heat vulnerability is not uniform: responses vary by age, geography, and time of year. Findings show that using pooled data obscures these differences, leading to misinformed policy and interventions. The authors argue for adopting more localized, seasonal, and age-sensitive climate-health approaches. They advocate future research integrating heat indices like WBGT and propose expanding this work to maternal and newborn health. The study emphasizes building a multidisciplinary heat research agenda, improving data access, and designing geographically nuanced public health strategies to address the growing risk of extreme heat.