Seal's Blubber (3.5e Equipment)
From D&D Wiki
The collected fat of seals can be a good screen against cold climates. When applied all over a character’s body, it provides a +2 bonus on Fortitude saving throws against exposure to cold weather. This is in addition to the benefits of winter clothing. One jar is good for five uses and each application lasts for 24 hours.
Cost 2gp; Weight ---