Is my new iPhone 12 a lemon? Will not hold a charge & runs hot.

Why is my new iPhone 12 running hot? Why won’t it hold a charge for even 4-5 hours? I’ve turned off EVERYTHING I can find to turn off to improve battery life & it still loses its charge (down to under 20%) in 4-5 hours. When charging it gets very hot!

Do I have a lemon?