Review on Doli Yearning Baby Bath Thermometer: Green Frog Shape, Room Temperature with Fahrenheit and Celsius, Ensuring Kids' Bathroom Safety - Plus, Fun Bath Toys! by Orwin Greener

I put the batteries in then dipped in water - after a little fiddling with the buttons on the back it worked! And unlike my old one which was just a thermal strip, I appreciated that it showed accurate temperature AND had a cold and hot warning light. Don't forget to take it out of the water when you're done or it won't turn off and keep flashing blue (because the water is cold). Don't worry, the frog will turn itself off if it stays without water long enough.