Rescuing people from burning buildings and serving with the military in a warzone require unflinching bravery.
So it would be easy to imagine that nothing could faze a Hampshire firefighter and former Royal Marine Commando.
However, they were dreading telling friends and colleagues that they had been struggling for years with their identity.
That the person they knew as Peter was actually Katie - a trans person who was undergoing life-changing social, medical and later surgical changes to finally live in her true gender identity and become the woman she was born to be.
Katie Cornhill was amazed at the positive reaction from her close work friends at Hampshire Fire and Rescue Service, which she says is trying to lead the way for the service - at a national level - and local community in terms of reflecting societies diverse gender self-identities.
The 44-year-old watch manager, from Southsea Fire Station, said:
“I don’t think I could have come out if I was still in the Marines – aside from the legal issues that would have created at the time.
“Before telling my colleagues I reminded myself that this is an organisation where people are dedicated to protecting people and making the community safer.
“My team were very supportive and quickly saw past trans identity, and realised I was still fundamentally me and still able and competent to do the same job.
“I don’t know how I could have done it without the support of Hampshire Fire and Rescue Service, which as an organisation supports inclusion, equality and diversity.
“The fire service has an important role in leading on this issue as they are an organisation that is held in high esteem by the public.”
Katie, who said she had known she was different since she was as young as five, said she lived her life in transition, openly since March 2012, before going ahead with her gender confirmation surgery last year.
She is now seen by many as a visionary and inspiring role model, helping to promote self, sexual and gender identity equality and equity, in part, as a trustee of Stonewall, which campaigns on issues affecting lesbian, gay, bisexual and trans people.
She believes that too many workplaces, in both the public and private sector, have archaic cultural barriers that hold them back.
Katie says those who lead institutions must realise that they should reflect the demographic model of society that exists rather than attempt to dictate it – she said the world is just not binary.
She recently appeared in the Stonewall School Role Models video alongside one of the charity’s co-founders, Sir Ian McKellen, the acting legend who played Gandalf in The Lord of the Rings.
Katie is also founder and chair of the UK Fire and Rescue Service sexual and gender self-identity support network quiltbag (www.quiltbagfire.co.uk) and is involved in changing attitudes through the Stonewall School Role models programme, the Diversity Role Models programme and as a progression mentor for The Prince’s Trust.
“I knew I identified as a girl when I was as young as five, and would dress up in nighties and try on clothes that were and still are stereotypically associated with cisgender females.
“But when I got older my parents tried to discourage this. I am aware that this was a protective course of action as they feared a negative reaction from family, friends and society that would be isolating for both me and them.
“I couldn’t repress my feelings and, with the exception of my ex wife and brother’s knowledge, I started living in stealth, only being myself when nobody else, apart from them, were around.
“When I was growing up there weren’t any gender-variant or transgender role models to help me understand and accept myself.
“I’ve never sought to be a role model but I think its important to acknowledge that to some I am.
“As a proud woman, a proud lesbian and a proud firefighter, it is wonderful to be able to help people realise they are not alone, to inspire them to be themselves, and to realise that they can contribute positively in organisations and to society as competently as anyone else does, irrespective of their self, sexual or gender identity.
“I just knew I was living in a skin that wasn’t mine.”
Katie recognises the need for workplaces and society in general to begin gaining an awareness now of the amazing diversity of modern self, sexual and gender identities that are rapidly emerging due to the supportive environment in education, including non-binary and intersex identities.
She is tirelessly campaigning to make things easier for other trans people and change attitudes that affected her, her relationship with her family and friends, and the very institutions that should have been there to protect her relationships, when she revealed who she really was.
“The institutional abuse and coercive control from individuals that I endured as a parent should never have happened, but it did. "Society must try and do all it can to learn from that experience and protect relationships.”