IT DOESN'T TAKE a lot of medical expertise to wonder if Washington's health chief may not be suffering acute delusions of grandeur--the kind that won't go away until somebody gives him a fireman's hat, some sirens, flashing lights for his car and a special firefighter's coat with "Public Health Commissioner" written across the back.

These are but some of the items on the I-want list of Dr. Ernest Hardaway, who already has a few little fun things around to play with, all courtesy of unwitting taxpayers: a $760 color console television set in the office to monitor his own interviews, thousands of dollars in communications equipment for the 1983 city-owned car he uses day and night and an $8,950 remodeling and repainting job done on his office suite. While we're at it, maybe we should throw in a red Rolls.

Oh, and about those office furnishings around the rest of the commission headquarters: "It's garbage, garbage, garbage, garbage," says Dr. Hardaway. "It's a perpetual embarrassment to me."

Far more embarrassing, however, is this entire display of excess at a time when local health programs are being cut sharply for lack of money; when clinics are being closed; when the medical examiner's office is reportedly critically understaffed; and when, until the story came to light, elderly residents were being told they would have to wait months for dentures.

Certainly a public health chief in a large city should be properly equipped for emergency service, even kept abreast at all times by beeper, radio or mobile telephone (though not all three, as is the case). But Mayor Barry should recognize that Dr. Hardaway's excesses are hard on the public blood pressure.