1. Temperature: This is the average kinetic energy of the particles within a substance. The higher the temperature, the faster the particles move, and the greater the thermal energy.

2. Mass: The more mass an object has, the more particles it contains. Since each particle contributes to the overall thermal energy, a larger mass means more thermal energy at the same temperature.

So, a bigger object (more mass) at a higher temperature will have more thermal energy than a smaller object at a lower temperature.