Worth testing so I knocked up an experiment. I wired 5 waterproof DS18BS temperature sensors in parallel and connected them to an Arduino Nano programmed to read them once per minute and record the results on a RaspberryPi (any computer would do). The sensors have a unique address, so the computer knows which is which: Then I insulated 4 used Coke Cans (330ml) with : 2 layers of Kitchen Tissue Paper, one layer of Card, 4 layers of loose Aluminium Foil. A fifth can was left uninsulated as a control. After inserting the sensors each can was filled with hot water from a kettle, covered with a pad of fibre insulation, and the Nano took measurements whilst I went walkies.