Rang my mum to ask if she'd pick us up a new one as most of us are ill (and I don't trust the in-the-ear jobby I invested in last year.. there's no way it's accurate) and asked mum to get an ordinary digital thermometer, you knows the ones, about the size of a pen, cost about £3-5.
Mum described them to the lady as the ones you can put under your arm or in your mouth as I described them to her.. Lady In Superdrug says you can NOT put them in your mouth!!
Why not??
We always have and we haven't spontaneously combusted yet!! I rinse the ends briefly under a tap as well!! And they generally last years on one battery!