The reason that cedar was traditionally used in chests and closets is because it is toxic to the moths that might destroy clothes. There was even a study done in Europe many years ago showing that rodents kept on cedar without a lot of ventilation had some health problems, too, although I can't remember the details. The reason that cedar is often used for rodents in spite of this, is probably because rodent cages usually have a lot more ventilation than reptile cages, and rodents generally have much shorter life spans that many reptiles. With shorter lifespans, many chronic or degenerative diseases may not show up before the animal dies of old age.
In summary, I would not advise using cedar in any close animal contact (including humans) except when there is a lot of ventilation, it is only for a short time, or the amount of cedar is very small (such as a cedar chest in a large bedroom with lots of ventilation - probably not a problem for people or other animals that only spend part of their time in the room. That is very different than as bedding or cage enclosure for a small animal 24/7).