What room temperature do skinks have to live in?

This question cannot be answered without knowing the SPECIES of skink, as skinks live on every continent apart from Antarctica, and in environments as different as deserts, tropical rainforests, and temperate grasslands.

All reptiles must have controlled heat of some kind to provide proper temperatures for digestion, so research the needs of the species you want to keep BEFORE you bring it home, and set up all of your equipment in advance.