In terms of warming, water imersion is an effective way of warming a body quickly so I can see how people can carry this idea over to hedgehogs (albeit not recommended!).
I have a few digital thermometers and they all show whole degrees only (no decimal points). I've ordered one with decimals but am waiting for it to arrive. My only concern with digital thermometers is how well its calibrated. I've compared several before in a relatively controlled environment and they differ by up to 2 degrees. That's part of the reason why I went with an industrial thermostat with hopes that it's calibrated better/more stable. Nonetheless, good to know... thanks Nancy.