 Heat kills workers. Indeed, searing days of 95, 100, 110 degrees are killing and injuring more U.S. workers each year than all the floods, hurricanes, and tornadoes combined. Those toiling outdoors, including farm workers, roofers and carpenters, airport ground crews, landscapers, road and street repairers, letter carriers, and trash collectors, are in the direct line of fire for this invisible, insidious killer.