It's nice to be in your undies when you're in the comfort of your own company.
I fully agree. I mean, who would you be wearing your clothes for? Just getting them wrinkled, smelly and worn out for no reason. And not just in +30 - my apartment's heating is very strong, it's usually very toasty in the winter.
Actually right now it's a bit cold in my apartment; the main heating hasn't been turned on yet and it's cooler now outside, no longer summer.