So I noticed, when I found a planet that has a lot of lava on the surface - The lava causes burning when I accidently land in it (the new gravity physics can be annoying, as EVERY planet seems to have little to no gravity right now...), but when next to it? I can still freeze to death... I dunno if this is an oversight, or not. But if it isn't, and hasn't been thought to be added - I suggest standing next to lava have the same effect as everything else including torches - And warm you up!
Adding a heat effect to lava would be nice but your just have a bad day with the gravity some planets gravities dont even allow you to jump a 3 block wall