During a hot flash, you might have: 
A sudden feeling of warmth spreading through your chest, neck and face
A flushed appearance with red, blotchy skin
Rapid heartbeat
Perspiration, mostly on your upper body
A chilled feeling as the hot flash lets up
Feelings of anxiety
 The frequency and intensity of hot flashes vary among women. A single episode may last a minute or two — or as long as 5 minutes. Hot flashes may be mild or so intense that they disrupt daily activities. They can happen at any time of day or night. Nighttime hot flashes (night sweats) may wake you from sleep and can cause long-term sleep disruptions. How often hot flashes occur varies among women, but most women who report having hot flashes experience them daily. On average, hot flash symptoms persist for more than seven years. Some women have them for more than 10 years.