Traveller Map crazy temperatures


Banded Mongoose
I have recently been playing about with the absolute superb resource that is the TravellerMap site.
There are two things I cannot understand.

I used Gloire as my example.

When it generates if seems to make a rather bleak desert world which seems at old with its "agricultural" description.
Under "Map Actions" is an option to "Remove the twilight zone", which then makes the green all blue and green as I would have expected. But what does this option really mean?

And "Atmosphere and Temperature details" strike me as somewhat extreme for many worlds I have examined.
Gloire has Upper Temperature Limit 1110°C

I wouldn't go there for a summer holiday.

What am I doing or assuming wrongly?