I am currently taking an online course in textile preservation through the Northern States Conservation Center. A little tidbit from my readings, related to the importance of environmental monitoring in museum and library areas with exhibits:
"One person can release approximately the same heat as a 60 watt light bulb and approximately a wineglass-full of water per hour." (Standards in the Museum Care of Costume and Textile Collections, 1998).
Which can, really, have a large impact on your collection if you have lot of people coming to an exhibit! Yikes!