Temp Light coming on

So…I’m out yesterday with the crew. 0c, 12in snow, breaking trail pulling a fairly step hill, low range 4×4, working it pretty good. When I stop and turn around I notice my temp light on, coolant fan is on sounds strong, coolant is full, not boiling over, doesn’t miss a beat running fine. Does anyone know if these temp sensors have bad calibration from factory? or? I haven’t checked valve adjustment for awhile…any info would be much appreciated.