What worked for me when I had my flashes for a couple of years was a Chinese patent medicine called Da Bu Yin Wan - I noticed an effect within 3 days! I took them on and off over a two year period, as needed. American ginseng is good too, as it builds vitality, plus it is a cooling and moistening form of ginseng(the regular panax it too heating - you don't want that right now). This is a whole lot better and healthier than going the hormone route, IMO. Your mileage may vary on this one, but looking into traditional Chinese medicine might be a good idea, as they have a long track record with dealing with women's conditions. If your condition is more severe than what a patent herbal formula would address, the acupuncturist will prescribe a custom formula of a bag of herbs to cooked up by you at home. This is the strongest form of the herbal medicine! Often, the drink looks and tastes exactly like mud-water, but trust me, these are good things(had this type of stuff for flu)! Acupuncture treatments, and especially the herbal formulas will really help balance out the body and improve one's general health and vitality. Plus in TCM the whole attitude towards women is different, not the patronizing one so commonly found in Western(esp. male doctors)medicine.
I haven't had experience with this, but supposedly Western herbs like black cohosh, etc. are good too.
A few Chinese dietary tips to reduce the dehydrating heat one has going on with hot flashes, is to either cut out(or seriously limit) the heating, drying culprits like coffee, hot spicy food(if that seems to aggravate your symptoms - if it doesn't and you like hot spicy then by all means keep it). Alot of meat(esp. red), sugar and alcohol make hot flashes worse too. The presence of these last three in the diet over a long period of time leading up to menopause almost guarantee extreme menopausal symptoms. As far as the meat(unless organic or wild), the presence of all sorts of antibiotics and hormones in it have something to do with it, and not in a good way either! So the Chinese indicate the dietary antidote(along with an appropriate herbal formula)is moistening, cooling foods - this a good time to get in alot more raw produce(both fruits and veggies)into the diet if it is not there already. Load up on those meal-in-a-bowl salads, with the emphasis on the greens, and a nutritious, homemade dressing. Simple soyfoods like tempeh and tofu are good too, better than taking the so-called soy supplements, which can be unbalancing. Cooling drinks like lemon or lime ice water are good, too, especially with summer right upon us, and very alkalizing, so much better and way cheaper than soda(avoid that stuff like the plague!)If you do some research on the web about Chinese medicine and diet most likely you'll be able to find lists of foods that are cooling and moistening.
Second, exercise, exercise, and exercise - this has to be part of your day. Strength training, Ashtanga yoga(very active, powerful, strengthening form of yoga that can have a HUGE effect on balancing hormones as one of its positive effects), and of course cardio of some sort.
Last but not least, ongoing stress will certainly make hot flashes worse, so anything you can do for "stress-busters" is especially indicated, like yoga, meditation, inner spiritual work.
If you do implement a several-pronged approach, the hot flashes will be safely addressed, and you can seriously improve your overall health in the process!
Hope this all helps!