Comfort Systems Usa, Inc.
A company that designs, installs, and maintains the heating, cooling, ventilation, electrical, and plumbing systems inside commercial, industrial, and institutional buildings — from data centers and factories to hospitals and schools. Founded in 1997 when a dozen independent regional mechanical contractors merged into one national firm, it has since grown through acquisitions while keeping local crews in dozens of cities. Fun fact: its ticker is "FIX," a fitting nod to the repair-and-maintenance work that makes up a big part of its business.