Slower particle speed typically correlates with a lower temperature in a substance. Temperature is a measure of the average kinetic energy of the particles in a substance. When particles move more slowly, it indicates that they have lower kinetic energy. Conversely, higher speeds of particles suggest higher kinetic energy and, thus, a higher temperature.
In thermodynamics, this relationship is key to understanding how temperature affects the states of matter and the behavior of materials. If you have a specific context or additional details regarding your question, please share!