Pelican cases are made from a resin actually, and I would be very surprized if they would break. They have a lifetime guarantee.
Call them and ask them what the low-temp specs are:
[email protected]
1-800-473-5422 (outside CA) or 310-326-4700 (inside CA)
Like the Starlite, Pelicans are airtight, watertight, and have a pressure relief valve for trips to high altitudes (like the unpressurized cargo hold of a plane).
Incidently, if you are planning on going out in extremely low temperatures; aluminum will become brittle too - and may shatter like glass if it is dropped on a hard surface.
[This message has been edited by LAK (edited 10-05-2001).]