Too low
No. That is too low.
You have them too low in the oven or the temp too high.
it would be considered a "low grade" temp.
DTC P3081 - Engine Coolant temp too low
Check the thermostut at first.  Your stut temp is too low. 
Then turn it up but to a safe level at least 80%
where you live? what was the temp outside when you checked the pressure? what was the temp in your space your trying to cool? question is too vague
try changing your thermostat.
Is it a 2.3l ? guage error is common on these! check with exteral temp. guage to verify actual temp. If low change thermostat, but be careful not to install it incorrectly. [uspside down]
Coolant Level too low (or sensor went bad) or Engine Compartment Temp too high / engine compartment fan failure
Yes it can. Every submarine has a maximum depth at which it is safe to operate. If it goes lower than its safe limit, the pressure can crush the hull.