My two have biotherm chips (they were done by the rescue before I got them) and my own vet's scanner reads them...she just runs the normal scanner over them, it doesn't seem to need a separate one.
I have heard that they're not necessarily that accurate but mine always seem to be about right, although I guess if there was a reason to believe it wasn't quite accurate enough for a particular purpose there's nothing to stop the vet from using the old botty method - but for a routine check it seems to be good enough.
They also don't work with some of the microchip catflaps so if there's a chance in future they will need access to one of these, it might not be the best idea...but other than that for the small initial extra cost I personally think it's worth it. Then it can be scanned for temp or not depending on the purpose of the temperature check.
