It is very important smokers "dispose of their cigarettes properly" this weekend during a seven hour walk-out by firefighters, the head of London fire brigade has warned.
The capital's fire commissioner, Ron Dobson, said his firefighters would not attend grass fires during the strike unless there was an imminent threat to someone's life or property:
A small spark from a cigarette is often all it takes to start a grass fire in these dry conditions so it really is important that smokers dispose of their cigarettes properly.
Drivers also need to take care not to throw cigarettes out of car windows as they can easily burn grass verges.
People barbecuing on open land should also make sure that they extinguish them properly when finished with.
There is contingency cover during the strike but it isn't a replacement for a normal service.