I still remember the days when I was a 6-year-old kid, and my mother comes with a glass stick (when I am sick,) then she tells me, "open the mouth darling." I asked her, "What’s it, mom." Then she says, "It’s a Thermometer darling.

Read More: https://www.wacvo.org/industrial/hero-of-alexandria-mentioned-about-the-earliest-form-of-thermometer.html