It's an icon representing a medical thermometer. The thermometer is pointing down and to the left. There are hash marks on it to show where the temperature would be and a line going from the base through the center of the thermometer.
This Warm icon is made in flat color style
. This format was developed by Icons8 designer team and became immensely popular for use in web and mobile applications. Feel free to download this icon in PNG format for free, or unlock other formats for $5. Unlike other icon packs that have merely hundreds of icons, this monster icon pack contains 6,100 icons, all in the same style and quality.