I don't no a lot about Greeks. However the keep them hot and dry is out dated bad info for almost all if not all torts. Look no place else then TFO for correct info.
Send a pm to GBTortoises if you don't get enough info on this thread.
WELCOME
Also, when we know approximately where you are, it helps us design our answers to better fit your questions.
A little bit of humidity helps babies grow smoothly. But humid and cold is a bad combination. Make sure if you go the humidity route, that you keep him warm.
If you're raising a hatchling warm (not "hot") and hydrated.
Hydration in the form ambient air humidity (55-75%), substrate moisture and keeping the tortoise well hydrated by either a constant source of clean drinking water or at the very least every other day watering (soaking).
What subspecies of Greek do you have?