How long is it safe to handle bearded dragons out of their controlled temperature zone?

I'm thinking of getting a beardie and I know that their vivariums are kept at very high temperatures to mimic their natural environment. So I was wondering, how long is it healthy for them to be in the 'cold' room temperature (18-20C) for? Is there a way to tell when they are getting too cold?How long is it safe to handle bearded dragons out of their controlled temperature zone?
I have mine out for hours but then they are usually on me so they are getting body heat. I have even wrapped mine up like a burrito and laid them on my chest while watching tv. Just use good common sense and watch for signs from your dragon.How long is it safe to handle bearded dragons out of their controlled temperature zone?
if there is a light on near where you have him/her out at then he/she will start walking towards it then you will know but i usually have my beardie out for hours and she loves it also if they run and hide that usually means they are cold and tired and want to go back to their ';bed';

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