well, what I have learned is 'don't leave it on the radiator'...so, that's my lesson 1 shared :D

This is from last year when the weather was getting cooler, I made a mistake on the thermostat... Now, I have a warming mat for mushroom cultivation that I'm going to dedicate to keeping my sourdough at-temp (living in England in Winter is not sourdough-on-the-worktop friendly)