You may have been at work or at play, or even at war. They do great things fast. Small companies may be hot groups in themselves.
Startups are often hot until their financial backers insist they grow up.
If hot groups are rare in large organizations, and they are, the exceptions are instructive. Even the U.S. government has hatched a hot group or two. Perhaps the most memorable was the brainy but politically diverse executive committee that President John F. Kennedy assigned to defuse the Cuban missile crisis. While none can claim to have quite the effect as the group that sent Khrushchev's warheads back to the Soviet Union, hot groups can be as important to the organizations that nurture them as they are to the individuals who take part in them. Unfortunately, real hot groups often don't survive organizational management.