Firefighters in London fear a rise in calls from people getting trapped in objects like handcuffs after the release of the “Fifty Shades of Grey” film on Thursday.

The city’s fire brigade said it had seen a rise in incidents involving people getting stuck in compromising situations since the release of the kinky book by British author E.L. James in 2011.

“The Fifty Shades effect seems to spike handcuff incidents so we hope film goers will use common sense and avoid leaving themselves red faced,” said third officer Dave Brown of London Fire Brigade.

Since April 2013, fire crews have been called to 28 incidents involving people trapped in handcuffs, and seven cases of men with rings stuck on their penises.

In November last year, a man had to undergo surgery to remove two metal rings stuck on his penis.

Doctors were unable to remove the rings, so two firefighters cut them off with a cutting tool.

In previous incidents firefighters have helped a man whose penis was stuck in a toaster, and another whose genitals were trapped in a vacuum cleaner.

Each incident costs £295 ($455, 400 euros), the service said, meaning the 472 cases of people getting trapped in household items in 2013-2014 cost taxpayers almost £400,000 ($616,000, 540,000 euros).

The fire brigade issued the following advice: “If you use handcuffs, always keep the keys handy” and “if it doesn’t look safe, it probably isn’t, so don’t do it!”