The P1S doesn't come with a enclosure sensor, so I got a temperature sensor from Ebay for a couple of dollars and designed a holder to place it in the excess cable can be tucked in behind display, just position and pull gently the length you require into the enclosure and secure the display holder over the hole at top of P1S with a bit of double sided tape.

To ensure accurate temperature readings, make sure the temperature probe is placed in a position within the enclosure that accurately represents the overall temperature.