In hypothermia, all biochemical events, including the kinetics of the currents responsible for pacemaker activity, for the maximal rate of rise of the action potential upstroke, and for repolarization are slowed. As a result,sinus rate will decrease, and P, QRS and T wave durations will increase, as will the PR and QT intervals. Hypothermia is also characterized electrocardiographically by a low amplitude positive deflection which occurs at the junction of the end of the QRS complex and the onset of the ST segment. This deflection is referred to as a “J wave” and/or as an “Osborn wave” , so named in honor of Dr. Charles Osborn who definitively described these deflections in 1953.