a method of measuring hot flashes based on the sensing of skin moisture incorporates a chip for sensing humidity . the method incorporates a chip for sensing humidity , and a risc micro - controller . a single tiny low - power device of about the size of a quarter is embedded into a reusable plastic housing . inexpensive and reliable objective measurement of hot flashes is achieved , along with advantages in size , weight , and extended durations of recording and data analysis periods . hot flashes are measured as a biomarker of the efficacy of clinical intervention in relieving symptoms of menopause .