Hand reaper hand

Rapid heartbeat when laying down to sleep? - rapid heartbeat and sport

Every evening, when my friend is expected to have a rapid heartbeat. Are there set up and take a deep breath in order to reduce the speed, is less heat in the bedroom. He is a big guy () 300 pounds, but is healthy. He lifts weights and has big muscles of the torso. Could do something with it? I am a little afraid for him.