More than 560 new recruits became regular officers at the annual Passing Out Parade at Hendon Police Training College.
Friday's ceremony, conducted at the facility in north London, was overseen by the "reviewing officer", Bernard Hogan-Howe, the Scotland Yard Commissioner.
More than 2000 people attended the ceremony, including dignitaries including Boris Johnson, the Mayor of London as well as family and friends.
During the ceremony witnesses reported up to 12 recruits felt the heat and passed out or collapsed despite temperatures only reaching 66.2F (19C).
A total of 567 Specials and PCSOs graduated, at what the Metropolitan Police described as the "largest parade" the force had ever conducted.
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Witnesses suggested that up to 12 recruits fainted during average temperatures.
On Friday night a Met Police spokesman could not say how many recruits had physically passed out, admitting only that it was a "small number".
Earlier Mr Hogan-Howe described the parade as a "great day for London".
He added: "Another 567 officers to patrol the streets of the capital is a great achievement.
"This is a historic event and the number of officers passing out here today at Hendon is the highest ever.
"I wish them every success as they start on their careers with the Met, helping us to keep Londoners safe."