Amazon upgraded warehouse AC system after saying worker’s death wasn’t heat-related

Amazon upgraded the air conditioning system at a New Jersey warehouse where it blamed 

 during a heat wave last month on a “personal medical condition,” according to three facility employees and photographs seen by NBC News.

One photo shows a large new ducting system installed on a ground floor of the warehouse in Carteret, known as EWR9, with the ducts pointing upward.

Workers said the equipment was part of a new industrial…