IDK about the UK.
I had an ex girlfriend who tried comitting suicide, and then warned me- I wasn't able to get to her so I warned her parents at the time.
(this was years ago)
her parents called the police/ambulance. They took her to the hospital, and forced her to stay with a bunch of crazies for 2-3 days if i remember correctly.
This was in canada, so, idk how different it is, but, IMO it would be a pretty cold and traumatizing experience being rescued by a bunch of out of touch bloomers.