The ornamental design for a hot and coldpack for medical purposes, as shown and described.
1.1 is a front perspective view of a hot and cold pack for medical purposes in accordance with the invention with attachment straps shown in broken lines;
1.2 is a front view of 1.1 with attachment straps shown in broken lines;
1.3 is a back view of 1.1 with attachment straps shown in broken lines;
1.4 is a left view of 1.1 with attachment straps shown in broken lines;
1.5 is a right view of 1.1 with attachment straps shown in broken lines;
1.6 is a top view of 1.1 with attachment straps shown in broken lines; and
1.7 is a bottom view of 1.1 with attachment straps shown in broken lines.
The broken lines are for environmental purposes only and form no part of the claimed design.