Blackfungi, I had to come in and thank you for this recommendation - I got one of these for MrDaisy who has taken it to a client site today to reduce his reliance on takeaway coffee ..
Got an email from him during the day with the topic
"coffee thermometer - I need one that says "Too hot", "Safe", and "Make another". This cafetiere has the best heat retention I have ever seen - or felt. "...Featuring the insulation they use in Hell.." I feed it a couple of shots of ice water to get it right-ish after it has infused for a while (but temp-testing method is still a bit old-school) and it holds that temp for as long as the coffee lasts. Awesome."
I just hope he remembers to put it back in his EB - it would take me a while to get another sent from the US.