The London Fire Brigade said it was facing a rising number of callouts for people trapped in handcuffs, blaming it on a best-selling erotic novel's "Fifty Shades of Grey effect".
In the past three years the fire service has rescued 79 people unable to escape handcuffs, as well as nine men with rings stuck on their penises, one with his penis trapped in a toaster and another in a vacuum cleaner.
"I don't know whether it's the Fifty Shades effect, but the number of incidents involving items like handcuffs seems to have gone up," fire officer Dave Brown said in a statement.
"I'm sure most people will be fifty shades of red by the time our crews arrive to free them."
British author EL James has sold more than 70 million copies of her erotic romance novels, a trilogy starting with the sado-masochistic tale Fifty Shades of Grey.
The fire brigade urged those using handcuffs in the bedroom to "always keep the keys handy".
It is highlighting cases of "people being stuck or trapped in objects like handcuffs or toilet seats" to try to reduce such incidents, which it says cost the British taxpayer at least NZ$554 each time.
Over three years London firefighters have responded to 1,300 cases of people trapped or stuck - more than one per day.
These included 18 children with their heads stuck in potties or toilet seats, five people with their hands trapped in shredders, and four with hands stuck in blenders.
One man's arm became trapped in a portable toilet, while another adult was wedged inextricably in a child's toy car and another got a test tube stuck on a finger.
Other cases include a child's head stuck in a massage chair, and a youngster unable to remove a tambourine on the head.
More than 500 cases involved people with rings stuck on their fingers.
"Our advice is simple," a spokesperson said. "If the ring doesn't fit, don't force it on."
"Common sense is needed," the brigade said, adding that members of the public should not hesitate to call them in a "genuine emergency".