How are they activated?

It’s activated when exposed to air, after you open the package. No microwaving or shaking required.

What's the expiration date? How long is the shelf life?

Our heat packs are shelf stable for 3 years from the manufacture date. Although they may still work after that, we can’t guarantee it. 

Are these heat packs reusable?

No, they are one-time use and cannot be reactivated once used. 

Can these be used to keep food warm shipping overnight?

Yes, they can keep food warm during shipping. Depending on the box size, you may need to use multiple packs. 

How much will they warm up an insulated box?

One pack will keep the inside temperature at 70°F in 1cu ft box. Use one pack per cubic foot and additional packs to raise the heat 10°F per cubic foot.

When will I receive them?

We ship everyday, Monday through Friday by USPS. Expect to receive your order within 3-5 days from order date.

What if I receive defective packs?

We guarantee all packs will activate upon opening. Although rare, any defective packs that don’t heat up within an hour can be returned for a full refund.