We investigate how occupation influences temperature-related mortality in Mexico. Using decades of nationwide death and weather data, we find that temperature-related mortality risk varies sharply by occupation. Young adults in climate-exposed jobs experience significantly higher heat risk: a 15-24-year-old agricultural worker is over 10 × more likely to die from heat than an age-group peer in professional/managerial employment. Cold temperatures also increase mortality, especially for older non-workers. Our results suggest that occupational safety and adaptation policies may protect vulnerable workers from death and that ongoing economic shifts away from exposed sectors may moderate future heat-related mortality.