Perturbations In Heart Rate And Heart Rate Variability Of Volunteer Firefighters Responding To Nighttime Calls: 2943 Board #3 May 29 1:00 PM ‐ 3:00 PM. (July 2020) - Coehoorn, Cory J.; Service, Thomas W.; Gawryluk, Jodie R.; Stuart‐Hill, Lynneth A.