Taking a temperature reading through glass is problematic, because most window glass is opaque to IR.
When I was a volunteer firefighter, one of the required skills was being able to use a thermal imaging camera (TIC). A TIC will show an image of the thermal IR sources in a scene. It includes a calibrated spot sensor that will measure and display the temperature of a small spot in the centre of the scene. It is useful in firefighting to measure, for example, the temperature of a chimney, to determine if there is fire inside it.
If you point the TIC at a window, you see only the glass. You don't see thermal signatures from the other side of the window. The spot sensor displays the temperature of the glass, not the temperature of objects on the other side it.
If you were to try to invent a remote sensor to read the temperature of objects outside a building, part of the invention would have to be the window that it looks out of, since an ordinary window will not work.