My T480 is fairly quiet unless it's under pretty heavy load. I do have the model with discrete graphics, which apparently has much better cooling (even when the discrete chip isn't being used).
All the laptops I've had over the years (HP, Dell, 2 Asus, now a Thinkpad, plus like 3 Dells at work) have idled at about 50 C. Is that not supposed to be normal?