BIG UNTRUTH My brother and I have taken 12 packs into Death Valley many, many times. . We just converted a backpack by sowing a small velcro cooler into it and it convineiently fits into the backpack. Now that being said . I haven't tried this since 9/11 . .so that may no longer be possible. However, in the past we haven't had any problem. BTW . .this isn't a flame . . I like the fact that I can do this . .