This is a deluxe shipping option for people living in cold climates! This kit includes a Styrofoam-lined box, a 72-hour UniHeat pack, PLUS an upgrade to Priority Mail to make sure your plants arrive safe despite the cold.
UniHeat packs keep an insulated shipping box warm for up to 3 days. They are highly recommended for tropical plants (Nepenthes in particular) being shipped when temperatures below 32 degrees are forecast. We only ship cold kit orders on Mondays to make sure the heat pack doesn't wear out over the weekend.
We have great success with this kit when low temperatures drop into the mid-teens. However, in the cases of extremely cold weather we may delay shipment until the kit can be used safely.