Of course it can't! It's a phone, and no matter what app or other software you install on it, it will never be able to read the temperature of its immediate surroundings unless you had some hardware already installed that can do so, and a touch-screen phone simply cannot take someone's temperature.
That does not mean that your phone becomes a thermometer and can read the temperature of the surrounding area, using a weather service.
A lot of idiots download this app and complain that their phone can't read the temperature indoors.
I previously used another thermometer app, but it had banner ads that you couldn't close, and they covered the temperature if it dropped low enough.
- It is a great app! It shows the temperature of your current location.