rick laid this down on his screen :
Thinking of using one of these temp sensor/displays:
http://tinyurl.com/jzrmp5n


Would need a 30mA DC supply ... 12-24V

Anyone know of small low cost DC supply modules ? ..........

I have a draw full of psu's ... laptop, router etc, I could use one of those
but as it only needs 30mA something small will be easier to house in an
existing box.

A pair of PP3 batteries in series would output 18 to 20v, just add a
push button for when you need to read it.