Why does thermal energy often go unnoticed?
The human body maintains a remarkably constant temperature. Sustained vigorous exercise or a significant fever can raise the temperature by about 1 degree Celsius. The amount of extra thermal energy required to raise the temperature of a 60 kg person by 1 degree Celsius is about 210,000 Joules.
In order for the person to have that much kinetic energy they would need to be moving at a speed of 84 m/s or 187 mph. About the speed of a formula 1 racecar!
In order for the person to have that much gravitational energy they would need to climb to a height of 357 meters. About the height of the empire state building!
So… an amount of energy that is just barely perceptible as extra thermal energy is dramatically obvious as kinetic or gravitational energy.
While this seems like a lot of kinetic and gravitational energy it is surprisingly inexpensive. In Seattle, you can purchase this amount of electrical energy for about half a penny!