It's quite warm here, like 25°C or something around. Maybe I cant take him to the sun or give him something to climb but he can barely move but I'll try the rest you say
I just found this guy in a box near my house.
He looks very weak, there is no vet around and he can't stick his tongue out when I tried to feed him a small cricket but it stayed out, he finally managed to put it back in after a while (as if he barely had the strength to do so) and now he can't...