The Kelvin scale measures temperature based on the kinetic energy of particles, but its application in empty space raises questions about temperature in the absence of particles. In free space, the temperature is influenced by cosmic microwave background radiation, which provides a minimal temperature reading. The discussion highlights that temperature is a statistical property of large collections of atoms and molecules, and cannot be defined in a void with no particles. Additionally, even intergalactic space contains sparse matter and radiation that contribute to temperature. Overall, the concept of temperature becomes irrelevant in a completely empty space devoid of matter.