<prompt> MCARDLEs maximum allowable sweat rate for 4 hours is3.5 ltr21 ltrs2.5ltrs4.5 ltrs  <response>: Mc Ardles maximum allowable sweat rate:4.5 litre 4 hours. Predicted 4 hr sweat rate P4SR in comfo zone is 1-3 L Parks Textbook of Preventive and Social Medicine, 25th edition, Page No. 792 