Abstract: 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.