Suggest you try the following test with each:
Cover the visible camera lens with paper or your finger, and observe.
Cover the thermal camera lens with paper or your finger, and observe.
You will realise that the FLIR is an extremely low resolution thermal sensor, little more than an optical picture with a heat overlay. Clever software making the fused image, but it assumes that the thermal picture is related to what it sees visually. Can be fun looking through say a window with it.
The Seek is at least a reasonable thermal resolution to start with.
Bill