POPLAR BLUFF, Mo. (AP) – Federal workplace safety officials blame heat exposure in last weekend’s death of a 23-year-old landscaper in southeastern Missouri’s Poplar Bluff.

The U.S. Department of Labor’s Occupational Safety and Health Administration said in a statement Monday that the worker from Dexter was assisting in tree-trimming efforts when he became overheated Friday afternoon. That’s when OSHA says the heat index reached about 110 degrees.

OSHA says the worker’s core body temperature exceeded 108 degrees, and he died the next day at a hospital.

His name hasn’t been released.

OSHA says the worker was on his fourth day working for a tree service based in Muncie, Indiana.