Where should gel packs go in a parcel box?

Gel packs go above and beside the product, separated from freeze-sensitive goods by a barrier and held so they cannot slide.

20 April 2026Updated 28 September 2026

Short answer

Gel packs go above and beside the product, because cold air sinks. For freeze-sensitive goods a barrier separates pack from product, and the packs are held so they cannot slide. The number of packs depends on box size, outside temperature and transit time.

Gel packs go above and along the sides of the product, because the cold air in a box sinks and cold spreading from the top wraps the load. A parcel can be turned on its side and passes through several transfers, so the layout is built for every face of the box, not only for the upright position.

For freeze-sensitive goods a cardboard or foam barrier separates pack from product, and the packs are conditioned before use; a pack straight from the freezer can freeze the product. Packs must not slide: a pocket or filler stops them collecting in one corner of the box.

How many packs are needed and where they sit depends on box size, outside temperature and transit time. The layout is therefore tried once for that box, load and route, then repeated exactly under the same conditions.