Golden Greek tortoises (Testudo graeca ssp.) are a fairly recent addition to herpetoculture. Golden Greeks require slightly different housing and care conditions than the more common Greek tortoises. They come from hot, dry regions and do not tolerate high humidity or cool temperatures well. Also, constant exposure to morning dew on the grass can lead to plastron shell-rot issues.
In most regions of the U.S. they require indoor housing. At the very least, most must be brought indoors at night year round and maintained indoors continually during the cooler months.
Ideally, daytime ground temperatures should be in the upper 80s (degrees Fahrenheit) throughout most of the habitat. A flat basking area should reach the mid-90s. Nighttime temperatures are best kept above 75 degrees to even the low 80s. Do not let them get cooler than 65 degrees unless you plan to breed them. Try to keep humidity levels well below 50 percent. They can tolerate a little more humidity as long as you keep the bedding dry and cage temperatures never fall below the preferred ranges. But even slightly cooler than ideal temperatures, coupled with either damp bedding or high humidity, invariably leads to respiratory issues. For all practical purposes, unless you live in the desert Southwest, consider these tortoises to be primarily indoor animals.