The temperature at which most enzymes in human cells are most active is usually 37.5 degrees Celcius. This is termed as optimal temperature.
Above this temperature, the structure of the enzyme begins to break down or denature . The reason behind this is that heat produces kinetic energy and as the temperature rises, more and more kinetic energy is released and is taken up by the enzymes.
The excessive kinetic energy causes the breaking of intra and intermolecular bonds in the enzyme structure and thus it begins to break down rendering the enzyme inactive.
