PICNICKERS on Wanstead Flats have been told to beware of sparking grass fires, as temperatures in the capital soar.

As London bathes in weather hotter than Bangkok, the threat of sparking fires in dry park land has greatly increased, according to the London Fire Brigade.

The fires are time consuming and difficult for crews to deal with as they spread quickly, killing plants and wildlife and putting nearby properties at risk.

Visitors have been asked not to leave camp fires or barbeques unattended and to extinguish them properly before they leave.

Bottles and broken glass should also be binned to avoid them magnifying the sun and igniting grass.

Safe disposal of smoking materials is also of upmost importance.