Tom I've used Dallas 1 wire sensors for the strap temp measurements I've had a sensor wrapped in a small heater and I've not seen anything to suggest that the RFI is intefering with it.
I used the Sparkfun breakout board for SHT15 for the ambient temp/humidity sensor
http://www.sparkfun.com/commerce/pro...oducts_id=8257
Voltage sensing is a resistor divider circuit feeding an AD port on the Ardunio and the current sensing is a Sparkfun breakout for ACS712
http://www.sparkfun.com/commerce/pro...oducts_id=8882 (I've not got that working correctly yet).
I'm using A Sparkfun Serial LCD unit
http://www.sparkfun.com/commerce/pro...roducts_id=812
Some overkill in this but I'm using it as a learning exercise, I've got a couple of other temp control projects in mind.
I'll attach my code (as is), as mentioned the current measurement stuff is not working properly and since adding in the current and voltage sensing I seem to have messed up the LCD (I suspect a connection problem).
Bob