We actually have a mercury 1 too, it's just a pain in the butt sticking it and the electronic ones in your mouth for a few minutes, whereas the 1 I bought you just put the thing on your forehead or in your ear and 2 seconds later it beeps and tells you your temp.
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I could never hear the beep of the one you stuck in your mouth so I got one for the ear which I can sort of hear. I use the little cozies from the old oral on my water pic. I'm not cheap I'm frugal. The cozies for the ear can be used longer then the oral ones BTW
In the old days when a mercury thermometer broke it was a harrowing experience as I seem to recall Seems like you might have got a dose of Vaseline but I really don't recall. And then there were those other places they wanted to stick them