<prompt> Translate the following text to EnglishA Msingi wa joto inamaanisha, isipokuwa chini ya sehemu ya B na sehemu ya 407, wastani wa joto la kila mwaka lililotumiwa na kitengo katika miaka mitatu ambayo kitengo hicho kilikuwa na joto la juu zaidi kwa kipindi cha 1997-2001.  <response>: 5A The term baseline heat input means, except under subpart 1 of part B and section 407, the average annual heat input used by a unit during the three years in which the unit had the highest heat input for the period 1997 through 2001. 