'I was homeless. Now I'm one of the most senior female firefighters in the UK'
Dr Sabrina Cohen-Hatton has an extraordinary life story.
She was a homeless teenager, getting her only hot meal at school and selling the Big Issue in the evenings.
She joined the fire service when she was 18 and has risen to Deputy Assistant Commissioner, making her one of the most senior firefighters in the UK.
She also has a PhD in Psychology and has written a book called The Heat of the Moment.
How did she make all this happen and what advice does she have?
Watch the video to find out.