FIG. 1 is a front view of an ornamental design for a cooling device in accordance with the present disclosure;
FIG. 2 is a rear view thereof;
FIG. 3 is a left-side view thereof;
FIG. 4 is a right-side view thereof;
FIG. 5 is a top view thereof;
FIG. 6 is bottom view thereof;
FIG. 7 is a front right upper isometric view thereof;
FIG. 8 is a front left upper isometric view thereof;
FIG. 9 is a rear right upper isometric view thereof;
FIG. 10 is a rear left upper isometric view thereof;
FIG. 11 is a front right lower isometric view thereof; and
FIG. 12 is a front left lower isometric view thereof;
FIG. 13 is a front view of a third ornamental design for a cooling device in accordance with the present disclosure;
FIG. 14 is a rear view thereof;
FIG. 15 is a right-side view thereof;
FIG. 16 is a left-side view thereof;
FIG. 17 is a top view thereof;
FIG. 18 is bottom view thereof;
FIG. 19 is a front left upper isometric view thereof;
FIG. 20 is a rear right upper isometric view thereof;
FIG. 21 is a left front isometric view thereof;
FIG. 22 is a front right lower isometric view thereof;
FIG. 23 is a rear right lower isometric view thereof; and,
FIG. 24 is a rear left lower isometric view thereof.