"The temperature and relative humidities were all over the place," she says. In one 24-hour period last summer, the relative humidity was as low 14 percent and as high as 58 percent. For museum artifacts that date back hundreds of years—things like bone, wood and textiles—that kind of swing in the room's moisture content can be lethal. Organic material swells and contracts and eventually splits, cracks or otherwise falls apart. The park service's own standards don't allow that. And forget about getting the Smithsonian to loan you something with those numbers.