The lower limit of temperature is absolute zero, which is -273.15 degrees Celsius or 0 Kelvin. This is the point at which all thermal motion ceases and particles have the lowest possible energy. Absolute zero is unachievable in practice as any real system will have some thermal energy even at very low temperatures. However, temperatures very close to absolute zero have been achieved in experiments, such as in Bose-Einstein condensates and quantum degenerate gases.
The upper limit of temperature is the Planck temperature which is about 1.41679 x 10^32 Kelvin. It is the temperature at which the gravitational force between particles becomes so strong that it overwhelms all other forces, leading to a singularity where the laws of physics as we know them break down. This temperature is associated with the Big Bang, the event that is believed to have created the universe. It is thought that the universe was at or near the Planck temperature during its earliest moments, and it has been cooling ever since.
