The heat packs go from room temp to 100 degrees within 4-6 hours, then stay at 100 degrees until their time runs out (72 hours for 72 hour packs, etc.)
On the heatpack it says how big of an area it will keep warm, so you don't have to guess how many to put in, but usually one will do just fine.
I usually ship priority with a 72 hour heat pack, overnight with a 40 hour pack.
You make a separate compartment out of styrofoam for the heatpack in the box, so that it wont come in contact with the bags. I wrap my heatpacks in newspaper and then wrap the newspaper to a piece of styrofoam and put the foam in with the heat pad facing AWAY from the shrimp.
Or you can do what I do in medium rate boxes, which is make a middle compartment out of foam dividers and put the heat packs in their own little foam section.
-- liam
On the heatpack it says how big of an area it will keep warm, so you don't have to guess how many to put in, but usually one will do just fine.
I usually ship priority with a 72 hour heat pack, overnight with a 40 hour pack.
You make a separate compartment out of styrofoam for the heatpack in the box, so that it wont come in contact with the bags. I wrap my heatpacks in newspaper and then wrap the newspaper to a piece of styrofoam and put the foam in with the heat pad facing AWAY from the shrimp.
Or you can do what I do in medium rate boxes, which is make a middle compartment out of foam dividers and put the heat packs in their own little foam section.
-- liam
