Well first off, the eye doctor will tell you when you first get them that you should take them out for naps, showers, swimming etc. however that doesnt have to be done.
I have mistakenly slept with them in all night a few times, only noticing it when i can see my alarm clock too clearly!, all that happens is they become very dryed out and almost stuck to your eye so you have to peel it off and imediatey soak it in solution
For a nap i wouldnt worry, depending on my mood i take them out. if i know im napping for more than 3 hours or so i take them out but not for an hour or two, worst that can happen is that they get sticky and you need to wet them…