During cool-down, teams are free to work on whatever they want. After working hard to ship their six-week projects, they enjoy having time that’s under their control. They use it to fix bugs, explore new ideas, or try out new technical possibilities.
Working on stuff outside of the shaping cycle. Usually, we try to focus on bugs, technical debt and exploring new ideas. The main idea is to do the stuff you don't have time for during the 6-week development cycle.
Cool-down phase takes place every 8-weeks after the 6-week Development - template cycle and it's 2-weeks long.
Read more in the Principles section in which all phases are explained in fine detail.