There is a forum under Mechanical Engineers for Heat Transfer and Thermodynamics. You might be able to find more of the folks you are looking for that might provide more insight there.
Some places for heat transfer engineers would be heat treating, foundries, forging, hot-forming, etc. Also of course OEMs that make equipment for the above industries.
Aerodynamics is a branch of fluids, so I would expect a lot of fluid specialists in creating vehicles (both flying and reducing drag of cars, trains, etc). Boat design as well.
-- MechEng2005