Many jazz musicians and pop entertainers are known to be cool. Kids nowadays want to look cool. To be cool is to do one's thing well and looking totally unperturbed. Jesus was definitely cool. Here's how we can be cool.
(1) Never judge anyone.
(2) Trust in God fully so that we do not worry nor get anxious.
(3) Show compassion for all.
(4) Be optimistic and joyful always.