IR near the visible range is associated with night vision because we use active night vision goggles that use an infrared spotlight at 850 or 940 nm wavelengths (700 nm is red). This is not particularly useful without an illuminator, you're basically just getting visible light amplification then.

Passive thermal vision that might pick out a warm object in the dark require sensing of ~10,000 nm/10 um infrared, a very different problem! And one that wouldn't​ be easy to solve biologically, as it basically requires being colder than the object you are sensing. Edit: but not impossible! https://en.m.wikipedia.org/wiki/Infrared_sensing_in_snakes