#I personally don't think reptile traits like having their temperature be fully controlled by outside factors translates 1-on-1 to anthros

[true-blue-sonic]

what if one day silver just randomly asked tails about the science behind body temperatures and heat transfer and stuff just because he wanted to know why espio is always so cold at night when they start cuddling but then in the morning he's always very warm

Cute! I can see Silver be very interested in how the world works, also regarding himself and the people around him. The explanation that he is a mammal while Espio is a reptile probably already is very interesting to him, and even more with the implications that follow. I can imagine him just hanging out with Tails one day and going like "When Es and I go to bed he's cold but when we wake up he's very warm, but I'm always warm, so why does Es take my warmth but I don't take his cold?" and Tails can explain some small things about thermodynamics to him to clarify this phenomenon. Plus, that would make Espio the Friend With Perpetually Cold Hands of the bunch, which I think is quite funny!