First of all Temp Does not affect the riser at all. So who ever you heard that from dont believe anything. The Temps would have to be very high in order to even achieve any measurable change. It is aluminum not steel. Aluminum if you didnt know disapates heat at a very fast rate much higher than steel. Thus one of the main reasons besides reduced weight that race cars use aluminum Blaocks. Second heat greatly affects the strands of your string and cables. Its relaxes the fibers and softens the waxes and allows the string to both stretch and get thinner. That is the main reason one starts to experiance loose servings and loose D loop. As a prcautionary I would reserve the center serving and then put on a new D loop do to the fact that the serving is most likely loose after the heat. Was it a factory center searving or was it installed on the bow. Factory center servings tend to get pretty loose because they dont generate enough tension when serving. If your getting a custom string in the future be sure that it is served under at the very least 300# of tension and nothing over 450#. This will keep your serinvgs the tightest and eliminate your peep rotation. Uneven tension on individual strands is what causes your peep to rotate. In affect by twisting the string you are equalizing the tension across all the strands. Like pete Shelpy wrote in a article not long ago a really good string wont require any twisting at all. though the string looks much cleaner and neater with it twisted up and two colors. Just my two cents as a experianced string builder