A police spokesman said they received reports expressing concern for the welfare of a man on the Newlands Shopping Centre car park roof in Kettering at around 3.15pm yesterday (Tuesday).
Police attended the scene along with fire and ambulance services.
At 11pm, the man came safely down from the roof and was detained under the mental health act so he can receive the support he needs.
Chief Inspector Julie Mead, a police negotiator, attended the incident and wrote on Twitter: "So in the middle of my gym session, I get a negotiator call out.
"Up on a roof for eight hours with a homeless man.
"He shared his story with us which was heart breaking. I also felt how cold it was for the brief period I spent with him in the elements."
CI Mead added that the police's mental health nurse talked with the man and they managed to get him to come down.
She added: "He was taken to an assessment unit for help and support.
"The incident really brought home the plight of those that sleep on our streets."
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