AstroAI, Electric 4-Liter Portable Cooler/Warmer Mini Fridge, Blue To achieve the quickest cooling, fill the fridge with beverages which have already been refrigerated The lowest possible temperature depends on the surrounding environment The fridge is designed to keep items warm, it is not designed to heat up cold items Hot items will stay warm for several hours after the portable fridge has been turned off, provided that the door is closed properly For maximum cooling, please ensure the back of the mini fridge is at least three inches away from a wall NOTE: Make sure to only run your cooler/heater while your vehicle’s engine is on or you risk draining your vehicle’s battery