everything stays in the obs, as mine is mostly timber with good ventilation, it stays at the ambient shade temp, i usually will have it open for 1 hr prior to serious imaging, which is time to check polar alignment, cool down time, shoot a few frames to check focus.
mind you stinking hot clear skies all day.... then at dusk in rolled the clouds
imaging nights in melb 0 for 2008 ... im going to keep a tally this year.