my buddy bought a cheap thermocouple that hooks right up to a digital multimeter. only thing is it doesnt read out like "160*F" or anything like that. it has some sort of scale, so itd display between 0 and like 5ish was the hottest he got. he siezes his metrakit all the time and he was actually able to correlate the heats to his siezures... we'd cruise and if he got above, say, 4.5 for a few minutes hed call the sieze and bam itd happen.
so thats a pretty easy way to do it but it dont tell you actual temperatures. if you were to take one heat reading, though, with a thermometer at say 2.5, then its linear so you could figure out the scale and know that when it reads 2.5, yer at 150 or whatever.