A.D.
This has been a subject of frustration for me for quite a while. I had one thermometer that I used on m boys rectally that is a digital one that is a "speed reader" -- just a couple of seconds and BAM reading. I thought I'd get one of the Thermascan kind (run it across their forehead and it is supposed to read the temperal artery) but it is NEVER accurate and there is always a different temp each time I take it. It's a $40 piece of junk. I also recently bought a new digital thermometer that supposedly has "modes" for taking the temperature... under arm, rectal and oral. (not that you'd want to use the same one for all regardless of if you use the plastic covers or NOT! eww) but you had to have instructions just about every time you used it b/c it was impossible to remember how to get it to read in each mode. I did like this one b/c it was flexible (material) and the first few times I used it orally, seemed to work well. Tried to use it recently on my 3 year old and I just couldn't figure out how to get it to do an under arm reading..
So good luck to you... don't waste your money on the thermal scan kind.. just get a normal one.... (digital reader)