Firefighters in London are being called out nearly every hour to rescue people who have locked themselves in or out of a building or vehicle.
London Fire Brigade (LFB) said in the last three years it had been called out to nearly 22,000 incidents of this type - 20 each day.
The brigade said it has been called out to people trapped in cemeteries, toilets and cupboards.
It estimated this costs taxpayers more than £5m.
In the period 2009-11, the brigade was called to:
- 2,287 incidents where people were locked in
- 1,613 incidents where people were locked out
- 1,409 incidents involving babies or children being locked in cars or homes
- 276 adults and 176 children locked in toilets
- 12 people locked in cemeteries
- 14 people locked in cupboards
- a woman stuck in a fridge and a man shut in a freezer
- a person locked in the luggage area of a coach
- a person locked in a crematorium with a child
- a person stuck in a recycling bin
LFB said it wanted to reduce these types of callouts, saying locksmiths should be called unless someone's life was at risk.
On Tuesday, the force will tweet about every locked in or out incident that its crews are sent to.
'Finished at pub'
Dave Brown, head of operations, prevention and response, said: "We get called to an absurd number of non-emergency incidents involving people who have locked themselves in or out of their homes.
"We've even had people call 999 to ask if we can come round and let them into their homes, but then ask for the fire engine to arrive at 11.30 once they've finished at the pub."
He added: "If it's obvious to our crews that it's not an emergency, we won't help and people may well find themselves left out in the cold."
Steffan George, from the Master Locksmiths Association (MLA), said: "In most situations, a locksmith should be with you within an hour.
"It's always advisable to contact a qualified and inspected locksmith, such as those vetted by the MLA.
"I'd even suggest storing the phone number of a local locksmith in your mobile in case you ever need it."