"If you can see it, flee it; if you can hear it, clear it."

On Duty Trustee: Inform participants and spectators when a thunderstorm watch is in effect. Tell them that play will be suspended as lightning approaches, what the clear-the-area signal is, where to go for safe shelter, (inside the concession building, vehicles, or the lobby of the Palos Heights police station).

The flash-to-bang method is the means of measuring lightning distance as it approaches. To use this method, count the seconds from seeing the stroke to hearing the thunder. For each 5-second count, lightning is 1 mile away. So, at 25 seconds the strike is 5 miles away; at 20 seconds the strike is 4 miles away.

It is strongly recommended that the clear-the-area signal be given when the flash-to-bang count is no less than 20 seconds (4 miles), especially when small children or a large number of spectators are at risk. Use the public speaker system in the trustee office to immediately clear the fields and advise people to seek safe shelter.

Stay away from tall individual trees, lone objects (e.g., lights or flag poles), metal objects (e.g., metal fences or bleachers), standing pools of water, and open fields. Avoid being the tallest objects in a field. Do not take shelter under a single tall tree.

Wait a minimum of 20 minutes from the last nearby lightning strike (flash-to-bang count no less than 20 seconds) before resuming activities. Use the public speaker system to announce a return to the ball fields.