A tall rubber eyecup, the kind that extends above the eye lens all around, not only blocks stray light while you're observing but acts as a miniature dewcap when you're looking away. The same principle works on large scales. The tree is a giant dewcap, and it can work for you too. If you'll be looking at only one part of the sky, it's nice to have trees around and behind you. Not just your telescope but your charts and accessories will stay dry longer.
Trees also reduce wind problems, but a slight breeze is a good thing.
Radiational cooling is slow and inefficient compared to heat transfer with the surrounding air, so even the mildest breeze will keep your telescope nearly up to air temperature. Then there's the observing umbrella, not a widely known accessory but one that works. A beach umbrella blocks the chill of absolute zero the same way it blocks the heat of the Sun. It can help shield all your gear and keep the chill off you too. The Heat is On There will be times and places where none of this is enough.