Granted that those who think of their stamp collection first instead of family and loved ones when facing impending watery doom of the type dealt by Frankenstorm Sandy are considered on a par with men who dress as women on a sinking ship to get a seat on the women and children first lifeboat, one should nonetheless have concern when humidity and wetness approaches valuable or rare stamps.
There's little that breaks a collector's heart more than mint stamps that have been stuck to an album page, or each other, in a box of bulk stamps. It is only good sense to make sure that the gummed backs of pre self-stick stamps do not touch other stamps. Many only need a little moisture out of the air to get stuck.
Many collectors have old collections that still have old stamps mounted with hinges. Unless you have your stamp room climate controlled, it is time to switch over to mounts. Hinges should really only be used on gumless used stamps -- that is especially true for today's collections, as for some time a hinge has created a stamp valued at significantly less than an unhinged one.
Beyond moisture, and in what appears to be a changing climate that will bring more water into our lives, it is a good idea to have sealable plastic boxes and bags handy, along with bags of moisture-sucking silica gel to assure your stamps are high and dry, even if the water rises to heretofore unthought-of levels.