The ornamental design for a wrist warmer, as shown and described.
FIG. 1 is a perspective view of a wrist warmer positioned inside of an unclaimed glove.
FIG. 2 is a front view of the wrist warmer;
FIG. 3 is a rear view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top side view thereof;
FIG. 7 is a bottom side view thereof; and,
FIG. 8 is a perspective view showing the wrist warmer positioned on an unclaimed arm.
The broken lines depict portions of the wrist warmer that form no part of the claimed design. The glove and hand shown in broken lines in FIGS. 1 and 8 show unclaimed environment and form no part of the claimed design.