The Truth About Hot Flashes

What Do They Do?

Q. What's actually happening in the body during a hot flash? A. "The hypothalamus likely gets information that body temperature is going up. As soon as the sensor detects that a woman's body temperature is above the threshold for sweating, she'll sweat, mostly on the upper body (from the sternum up). Almost at the same time, there is peripheral vasodilation in your hands, arms, feet, legs and face. The combination is what causes flashing."

Q. Is there any benefit or downside (besides temporary discomfort) of having a hot flash? A. "Nope, nothing that we can think of. We're almost done with a sleep study, and the latest results show that flashing and nonflashing postmenopausal women, and even premenopausal women, all sleep about the same."

Q. How do you measure hot flashes? A. "We have three temperature- and humidity-controlled laboratory rooms, with beds and reclining chairs. Each patient is connected to a polygraph, which records physiological data, including heart rate, sweat rate, skin temperature, and rectal temperature. In most studies, we also measure core body temperature by having subjects swallow a telemetry pill, which measures core temperature about every thirty seconds and reports the information to a small recorder (worn on a belt) until the pill is excreted."