My absolute favorite part of Fed Ex envelopes, is where they say "Do not ship liquids, blood, or diagnostics in this packaging."  Oh, no!  What am I going to do now?  Actually, that's really rather gruesome.  Imagine a Fed Ex package being delivered to you and you open it up and it contains blood!  Or some other unmentionable liquid.  Do they have a special package specifically designed for shipping blood/bodily fluids?  If so, my office doesn't have any.