The Center's policy with regards to the turf fields and safety has two components, and trained turf marshals on these fields tracking the following parameters:
1 - HEAT - if the temperature at 4'6" (four and a half feet) above the field exceeds 100 degrees in the shade (or if conditions feel excessive to the marshals or other Center Staff), play is halted and the field cleared until the temperature cools to 94 degrees. At this time we may implement the water cannon cooling system, but we have found that there is not an appreciable improvement to safety with this system, it's more of a fun way to cool off. This condition occurs often during Summer. Grass fields are much cooler.
2 - Lightning - thunder claps or visible lighting or indications of electrical activity will close the turf area and clear not only the fields but also the bleachers for safety until 30 minutes of no indicators are recorded. The rationale for this policy is the same as lighting and swimming pools, which the turf fields can simulate. The occurances of this condition is rare.