A 23-year-old ground crewman is one of 16 heat-related deaths reported to OSHA since January.

The Townsend Tree Service Company worker collapsed after working more than nine hours in the direct sun when the heat index soared to 110 degrees near Poplar Bluff, Ind. on July 22. The crewman died after being hospitalized with a core body temperature above 108 degrees.

OSHA issued the company, based in Muncie, Ind., one serious citation following its investigation. Proposed penalties total $12,471.