(CNN) A 69-year-old FedEx worker has been found dead outside a delivery hub in western Illinois, and police believe the extreme cold snap that hit the country this week played a role.

The man, whose name wasn't released, is among 23 people killed in the United States as a result of extreme weather conditions this week. Cook County, Illinois, which includes Chicago, announced three deaths on Friday, including a 92-year-old man.

At the FedEx delivery hub in East Moline, a coworker found the man's body outside between two tractor-trailers Thursday morning, police Capt. Darren Gault said.

It wasn't immediately clear how long the worker had been there, or why he was there. The hub had been closed on Wednesday.

It was extremely cold in the Moline area this week. At an airport only 10 miles from the hub, temperatures dipped below zero late Tuesday afternoon and never rose above that until Thursday evening. Wednesday evening's low was 29 below with a wind chill of 34 below; Thursday morning's low was 33 below.

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