The ornamental design for a rescuetube, as shown and described.
FIG. 1 is a perspective view of the rescue tube;
FIG. 2 is a top view of the rescue tube; the bottom view being a mirror image thereof;
FIG. 3 is a right side view of the rescue tube; the left side being a mirror image thereof; and,
FIG. 4 is a front view of the rescue tube; the rear view being a mirror image thereof.
The broken lines shown in the drawings illustrate portions of the rescue tube that form no part of the claimed design.
The rescue tube is shown with a symbolic break in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design.