What's your age? You're not close to menopause, are you? I didn't experience hot flashes (what I call them) until a year or two before menopause. I still have them occasionally even though I'm well past "the change" now. I run outside too. Usually that stops them. If I can't run outside, then I go around fanning my face saying "whew, whew, whew." Another thought...have you had your thyroid hormones checked recently? I think that's also a symtom of hyperthyroidism. I'd have to check it out to be sure.
