You must have means of detecting a fire and warning people.
The means of giving warning of fire should be suitable for the particular event or venue, taking account of its size, layout, numbers of people likely to be present and the nature of the event.
For many open air events, the people present are the most practicable solution for fire detection and a shout of ‘fire’ may be all that is required. Where a shouted warning is insufficient, a manually-operated device such as a gong or air horn that can be heard by everyone may be appropriate.
At larger, more complex sites, a public address system is likely to be the most effective means of providing a warning and directing the evacuation. In larger structures, tents or marquees, a simple warning may not be sufficient. An electrical warning system may be required incorporating sounders and manually-operated break-glass call points.
In all cases, sufficient stewards or marshals should be trained and available to ensure the emergency action plan can be implemented swiftly on hearing the alarm.