As with many chameleons, they tolerate relative low night temps if they have the opportunity to bask in the morning. I once "forget" a small thamnobates juvenile outside and till I noticed this fault, it has to survive many nights between 0-5°C ! Fortunately it doesnt seem to have any problems with this. Because of this tolerance I plan on keeping all my Bradypodions in the future for more than half of the year outside, if its getting too cold they will be put in a greenhouse