Could you please help to provide the Theta-Jc of ADM1192 and the Max Ta of ADM1192; I can't find them in datasheet.
the ADM1192 is a low power device, consuming 2mA of current. At 26V that's less than 55mW.
With a TJA of 137degC/W that means less than 7degC temp rise from ambient for the junction.
The case temperature will most likely be just a couple of degrees above the die temperature.
If you use this device at 12V then power dissipation will be even lower.