What's the relationship between kinetic energy and temperature?

Kinetic energy and temperature have a directly proportional relationship with each other. As the temperature of an object rises, the average motion (kinetic energy) of its particles increases. With this increase in particle motion, the object's overall thermal energy also increases. Consequently, when an object's temperature rises, its thermal energy increases as well. Since the mass of these particles remains unchanged, when the temperature increases, the particles must accelerate and move at higher speeds. 

According to the kinetic-molecular theory, the temperature of a substance is connected to the average energy of its particles. When a substance is heated, part of the absorbed energy is stored within the particles while the remaining energy increases the movement of these particles. This increase in particle movement corresponds to a rise in the substance's temperature.