40 hour UniHeat heat packs (shipping warmers) activate in approximately 40-50 minutes. They are slightly cooler than the 30 hour heat packs, and reach their peak temperature in approximately 15-18 hours. The 40 hour shipping warmers are the most popular for those who are shipping reptiles, amphibians and insects. Not recommended for 2nd day shipping.
Under “Shipping Tips” found at the top of the home page, please see our complete guide on how to properly use and choose which UniHeat heat pack product is right for your shipping needs.
Price per Unit (piece): $1.25