With out a doubt one of the most important criteria for running and managing big projects or teams. Is the ability to keep your cool when everybody else is flapping around like chickens. The ability to deal with stress could be described as, how big is your capacity? What do you do when things go wrong? Bury your head in the computer.  One of the most important strategies is to handle things calmly. What can seem like the end of world one day. Will a day later seem like a mild problem and a month later nothing more than a little annoyance.
The reveres is true of course if one lost their temper and shouted at somebody or sent a very direct email. Work and relationships that have been built up for years could be lost in a fraction of second.  So if you want to master the situation. Keeping cool is the winning trick.