The thermostat may read 90 degrees Fahrenheit outside the sprawling federal research complex in Lakewood, Colorado, but inside, CU Boulder undergraduate student Casey Vanderheyden is donning a bulky winter coat, gloves and boots as though she is headed to the South Pole. In a sense, she is. Vanderheyden is reaching the end of her six-week summer work stint at the National Ice Core Laboratory (NICL), one of the country’s most prominent storage facilities for ice samples collected from around the world.