Not sure which variant that is, but looking at the base data sheet I see this:
Linear + 10 mV/°C Scale Factor
0.5°C Ensured Accuracy (at +25°C)
Rated for Full −55°C to +150°C Range
So 842 gives me 84.2 degrees above the base of -55 which is 29.2. Is that close to your ambient temperature?
Edit: typo (autocorrect)