Uniheat 60+ Hour Shipping Warmers are single-use disposable shipping warmers that are designed for steady heat release in closed shipping containers. The packs are individually packaged and easy to use. Simply open up the outer bag to expose the pack to air. Pre-heating is not necessary. Do not allow the shipping packs to get wet as this will instantly and permanently deactivate them.
* One warmer can generally raise approximately 10° to 15° in a cubic foot insulated box
* Warmer may stop generating heat if temperature inside the shipping box falls below freezing