Magic-users depend on much more than books in their profession. Potions, concoctions, herbs, and even ink can suffer from exposure to sudden drops of temperature. Hence this spell:
Proof Against Cold
Spell Class: Magic-user
Spell Level: 3
Duration: 1 day per level of the caster upon exposure (also see below)
This spell provides total protection from normal cold and frost for objects that would ordinarily be susceptible to damage or alteration from ice or excessive cold, e.g. liquids, certain plants, etc. The amount of material that may be so protected is equal in mass to one heavy book per level of the caster. This spell also provides limited protection from magical frost, e.g. cone of cold, ice storm, cold-based breath weapons, etc. Any object protected by proof against cold is entitled to a +2 bonus to saving throws made versus the appropriate magical cold-based attack. Any such saving throw is made as if by a magic-user of the same level as the caster who originally cast the spell at the time the object received its protection. A successful save means no damage was sustained by the object. The spell remains dormant until it is activated by exposure to destructive cold (with or without ice). Once activated, the protection lasts for one day per level of the caster or until three saving throws have been rolled (whichever comes first).