Rotomolded ice packs vs cheap gel packs: Rotomolded wins for serious coolering

Rotomolded packs have a hard plastic shell with welded seams that don’t leak, last years, and stay cold longer. Cheap gel packs are heat-sealed and fail after a few freeze-thaw cycles, leaving blue goo in your cooler. Rotomolded costs more upfront ($15–$30) but won’t quit; for short lunch trips, thick ice cubes in a ziplock work fine.