There are plenty of affordable thermal imaging cameras on the market. If you need one for serious jobs, you will need to invest serious money. The FLIR E95-24 is worth a look. It is an advanced thermal imaging camera with 464 x 348 IR resolution and 24 degree lens. It comes with laser-assisted autofocus for on-screen area measurement.
You can record thermal timelapses for up to 24 hours. The device makes the data available on the FLIR Tools app via WiFi. The device can handle high temperature measurement up to 1500C.