We add a super, or multiple supers, to give the bees space to store honey. The logic is that as the beehive fills up with bees, they will develop a bigger and bigger workforce. This workforce can travel to more flowers and produce more honey.
When you start a new hive, my general advice is to be a little more gentle with these bees. Super slightly more slowly, and inspect your hives carefully.If you started a new hive from a package, or a split and the frames in the brood box are not completely drawn, supering a hive may slow the whole process down.
Beeswax melts at nearly twice the optimal body temperature of a bee. This is possible because the bees take two broad families of compounds that melt at approximately their optimal temperature, and react them together, to make a family of compounds that melt at twice their body temperature.