Library Scarf
Scarf knitted and gifted by a loved one
Wizard schools are rarely built for comfort and more than one would-be scholar has caught a chill while pouring over inscrutable tomes or stuffy old biographies in drafty libraries in the wee hours of the morning. Given that bonfires are generally frowned upon when surrounded by books, creative apprentices were forced to investigate other means to get them through long nights of studying, resulting in the creation of these enchanted trinkets. Each appears as a simple woolen scarf of whatever color or pattern its creator chooses. When you use a bonus action to speak its command word and expend 1 charge, the scarf magically warms you for 2 hours, providing comfort and protection from cold temperatures down to freezing (under more frigid conditions, each charge insulates you for 1 hour).
In dire circumstances, the scarf can offer more significant protection. When you take cold damage, you can use your reaction and expend 3 charges to gain cold resistance until the end of the round.
The scarf has 3 charges and regains 1d3 charges each dawn. If you expend the last charge, roll a d20. On a result of 5 or less, the scarf loses its magic and becomes a mundane item.