A group of six students decides to conduct an experiment about "brain freeze,” a phenomenon that often occurs when eating something cold. The students each flip a coin. If they flip heads, they eat a cup of Italian ice as fast as they can while sitting in an air-conditioned car. If they flip tails, they eat a cup of Italian ice as fast as they can while sitting outside in the sunshine. After a recovery period, they each complete the opposite treatment. The students record the amount of time it takes, in seconds, for them to experience brain freeze under each condition.