On occasion, a large block of ice crashes down in the vicinity of a climber, producing a blast of displaced air and snow that can result in a "dusting" from a billowing cloud of light ice and snow—a very unnerving experience. A climber caught in an avalanche or other "movement" event in the icefall can do very little because it is not possible to run away or even to know which direction to run; therefore, climbers train for entrapment by heavy blocks of ice as well as rescuing others.