Until the mid-1970s, nobody paid very much research attention to the hot flash, other than as one more menopausal symptom to be snickered at along with other unkind references to mid-life changes in women.

In the mostly male ob-gyn community, the hot flash was regarded as a benign, but probably psychological symptom of menopause, easily treated with estrogen replacement therapy. Indeed, what research there was showed a clear link to estrogen deficiency, but the doctors remained fond of the belief that it had to do with a woman's fear and (or) depression about losing her child-bearing capacity and thereby, somehow, her sexuality.

The first, still widely quoted "study" of hot flashes was done in 1975. It had a research sample of one--the wife of the researcher, a physiologist.

Subsequently, in accordance with the trend to answering the newly vocal demands from women both in and out of the health professions, there has been a quickening of research interest.

University of Utah Ph.D. nurse-physiologist Ann M. Voda has established in a survey of 67 women (with a total of 1,041 hot flashes in six months) some of the most elaborate data available about the length, intensity, triggers, location and common methods of coping with "flashing." Her work also suggests that "upwards of 85 percent of women who enter the menopause will experience hot flashes." Even a higher percentage of women having hysterectomies in which ovaries also are removed will suffer some degree of flashing.

Says Voda in the current issue of "The Menopause Update," a journal of the Center for Climacteric Studies at the University of Florida, "There is no pattern to the hot flash. In other words, my hot flash experience will be different from those of other women.

"The one symptom that takes women to the physician to get relief is the hot flash. As part of the stereotype that has been built up around it, women who experience hot flashes have been said to almost lose their minds."

Because "much of the literature implies that the hot flash is psychological," says Voda, "we needed to know what triggers it ." On the basis of her study, it became clear that "contrary to what might have been expected, emotional factors rarely triggered the flash."

The Update, which is changing its name to the Clout (for "Climacteric Outreach") Quarterly to accommodate information about male middle-year changes, also contains a rare scientific article on probable physiological mechanisms that produce the flash.

According to the physicians, Dr. Isaac Schiff and Dr. John S. Rinehart, both gynecologists at the Harvard Medical School, what happens in simple terms is this: For still "obscure" reasons, somehow related to withdrawal of the female hormone estrogen, the body's thermostat (in the brain) is "reset" to a lower level.

"The body seems to receive an erroneous message that it is too cold, so it obediently goes into its get-warm mode, as it were, by dilating the skin blood vessels causing more blood to rush to the surface. This creates overheating (and a reddish flush), which is then physiologically compensated for by profuse perspiration.

In her forthcoming book No More Hot Flashes and Other Good News (G.P. Putnam's Sons, $14.95), Dr. Penny Wise Budoff writes that "although the flushing episodes are relatively short-lived usually up to five minutes it takes the body nearly a half-hour to regain 'normality.' If flushes occur many times per day, this temperature-regulating dysfunction is constantly overheating and recooling the body for many hours of the day.

"If the brain is spending large blocks of time processing such abnormalities, this may well influence the well-being of the woman with incessant hot flushes."

A word on terminology: Probably because the scientific study of the phenomenon is so new, not all the physicians and researchers have yet agreed on the vocabulary.

Schiff and Rinehart distinguish between the hot flash and the hot flush. The first is the "very subjective feeling a woman experiences prior to a physiologically measurable change--the flush."

Budoff, uses "flash" in her title because it is "popular," but in the text refers to "hot flush" because it "is the more technically accurate term."

The authors of another forthcoming book, Menopause ($15, W.W. Norton & Co.), Winnifred Berg Cutler, Ph.D., Dr. Celso-Ramo'n Garci'a and David A. Edwards, Ph.D. simply call a flash a flash throughout.

But whatever it is called, for some women it is a nightmare, especially when accompanied by night sweats, as often occurs. Sleep disturbances, the embarrassment of the sweaty flush when it occurs in public and the simple discomfort can be stressful and depressing enough to cause major behavioral changes.

Happily, even while the underlying causes are dimly comprehended, pharmaceutical relief for the most serious cases and coping strategies for the rest are available:

* Estrogen-replacement therapy, newly combined with cycles of progesterone replacement, are proving safe, even beneficial beyond their control of the flushes. Useful especially in the particularly disabling hot flashes that can last for years in some women.

* Biofeedback training can help control the intensity and duration of the episodes. (It is the same training that helps abort migraine headaches--learning how to warm your hands from within. The theory is to go with the flow, instead of trying to fight it.)

* Stress-reduction and learned relaxation techniques in general can have a beneficial effect on the physiology that can help regulate body temperature controls, among other functions.

Other techniques suggested by participants in Ann Voda's survey work best for milder attacks:

* Imagine throwing yourself into a snowbank.

* Drink something cool.

* Sit in front of a fan.

* Dress in layers and shed as needed.

And it may not be all bad. One woman, raised in a relatively mild climate, had her first hot flash during a particularly cold Wisconsin winter. "It's the first time," she sighed, "I've been warm in the winter since we moved here."

For more information: The Center for Climacteric Studies, University of Florida, 901 NW. 8th Avenue, Suite B1, Gainesville, Fla. 32601. On biofeedback training to control hot flashes: Georgetown University Family Center, 4380 MacArthur Blvd., D.C. 20007. Phone: 625-7815.