As the heat wave in the city wears on, Hollywood star John Gennaro (Leo Rossi, "The Accused") attaches himself to Mick and is in awe of the detectives' approach to his work and life. Frank takes the allegations leveled against his precinct seriously and determines to root out any possible wrongdoing. Lucy & Joe arrest a man named "Smith" (Robert Gray, 'Harper Valley P. T. A.') who claims to be an extra-terrestrial who desperately needs contact from his "people". Hollywood types played by Margot Rose ("48 Hrs.") and Floyd Levine ("Braddock: Missing in Action III") appeal to the local gangs for their cooperation during the movie shoot, promising them some sort of compensation. And Andy & Bobby arrest a drunk driver (Michael Fairman, "Thirteen Days") who turns out to be a city councilman; Chief Daniels subsequently leans on Frank to let the man go.
'Heat Rash' is another exemplary example of both serious material and humor; for one thing, the subplot with "Smith" is paid off in an amusing kind of way. Unfortunately for Gennaro, he ends up rubbing Mick the wrong way, leading the detective to declare what he thinks of all Hollywood hairbags. (This whole subplot predates the hilarious 1991 feature film "The Hard Way" by nine years.) Frank ends up receiving some very unfortunate news regarding Henry, who ended up doing something quite naive (some people might even say stupid). But it just goes to show how sensitive and compassionate the character was at that point. The bit of business with the councilman brings to light the fact that sometimes there simply is no justice, and sometimes people in positions of authority get away with too much for too long.
It is nice to see J. D. offer some apology after the tense period between him and Neal, and it is similarly nice to see Fay visit the precinct under some sort of official (however dubious) business. A poignant story thread finds Howard much humanized when he fears that he may have cancer. Much tension is derived from the premise that ordinary phone usage is temporarily on hold during the heat wave.
'Heat Rash' is capped off with another of those likeable tender scenes with Frank & Joyce, with one final comedy touch regarding the fate of an air conditioner.
Also guest starring Trinidad Silva ("UHF") and David Caruso ("First Blood"), in their recurring roles, Mario Gallo ("Revenge of the Ninja"), Paul Mace ("The Lords of Flatbush"), Jesse D. Goins ("RoboCop"), and Armin Shimerman ('Star Trek: Deep Space Nine').
Eight out of 10.