I spent some years in a Middle Eastern country with high ambient temps and several times per week taxied steel braked 747s several miles to run up areas.The aircraft were empty with low fuel loads and as a result tended to keep accelerating due to high residual thrust - company procedures insisted on 4 engines running.Trying to keep to a constant speed overheated the brakes rapidly.It was found that a single hard application to bring the aircraft almost to a standstill then allowing it to accelerate prior to a single application before turning kept the brake temperatures to an acceptable level.Whether this technique would be applicable to carbon brakes I do not know but it appeared to permit the least heat input and the longest cooling period.