Always. I'm not a fan of a/c and get enough of it at work. So windows open. fresh air to breath (maybe a little fan going) and complete nudity. I think clothes disconnect you from your body. Nudity is very grounding. Also love to take a quick snooze laying out in the sun on weekends.
naked is relaxing.. when have to will sleep in just underwear or more often fly fronted sleep pants .. the sleep pants making it easier to remove if one gets too hot in bed.. and when dating often sleep naked with my lady as I enjoy rolling over and feeling them close when spooning or being spooned.
being naked makes the feel of the freshly washed sheets the more enriched as they glide across one's body. Whenever possible will lounge naked as do not really enjoy being clothed, and enjoy the company of others who are like minded
I've slept nude ever since I was about 10 years of age. Don't possess any pj's but might sometimes resort to wearing a tee shirt in winter. Getting dressed to go to bed makes as much sense as wearing anything to go swimming.
Hell, I sleep nude all year round. It really is more healthy to do so, and if I have a Female partner, I will cuddle with her and eventually convince HER to cuddle with me naked. Yes, it might get in the way of sleep, but eventually you pass out in each other's arms.