P.E.A.E.

Hello. first of all sorry if my english is hard to understand but english aint my native language. I wonder if somebody has done an experiments to look if time goes slower among warm objects compared to cold objects? I´m thinking like this. I´ve learned that time goes slower for an object the closer to the speed of light it gets. And that time goes slower the more mass an object has So by Einstein laws for example a clock on a ball that weights 1kg that travels at 50% of lightspeed will show the same time that for example a clock on a ball that weights 2kg but travels somewhere less than 50% the speed of light, According to Newton laws both have kinetic energy in form of mass and speed. But if one make one of the balls have 50 degrees kelvin and another 200 degrees kelvin then one of them will have more energy in it. and will time also change so it goes slower for the 200 kelvin ball? Another thing I wonder has to do with E=mc2. The more mass an object has, the more energy it has, and i have learned that the more mass an object has the more gravitaional pull it has. does that mean that energy in form heat i applied on a mass, the more gravitational pull it will have?