Holly, 21, was running the Brighton Marathon when she suffered from heatstroke and collapsed after 27km.

It was a gorgeous day in Brighton. Really sunny, crystal skies. It was my first time running a marathon, but all the training had gone well; my target was four hours.

I’d been training in Amsterdam as I was studying abroad, where it had been a lot cooler. I wasn’t naïve to the risks of the heatstroke, though. I had my hydration pack, my hair was tied back, I’d tested all my running kit. I wasn’t being silly about it. I just don’t think I considered it a real possibility.

There were some warning signs during the race. When I stopped for the toilet, I noted my heart rate was very high. But then you think it’s just the adrenaline, because it was the first marathon I’d done, with that race element and atmosphere. Your body is naturally going to struggle in a marathon as well, so I didn’t think it was really any more than that. You just have to push through it. I didn’t consider these as signs of heatstroke, even though I know now that I was overheating and really struggling.

The last thing I remember was trying to open my gel. I was trying to open my gel and it wasn't opening. I was like, ‘Oh, I'll just get someone to open it for me’, because my parents were at 30 kilometres waiting to cheer me on. So I was like, ‘I'll just wait it out. It'll be 15 minutes. It's fine.’ And that was the last thing I remember doing.

The next thing I knew, I was lying on the ground with four St John Ambulance volunteers surrounding me. It was a really surreal experience. Half my clothes were off, I was covered in ice packs and drenched in cold water.

They took my temperature and were quite worried about it because it was super high, but they just kept cooling me down. They were absolutely phenomenal. They really just made me feel super comfortable.

My brain just wasn’t functioning in the way I was wanting it to.

I was calling my boyfriend my girlfriend. I still thought I was in Amsterdam. They asked me if I knew my mum’s phone number and I couldn’t remember it, even though I’d known it since I was seven. When I looked at my Strava the next day, you can see the pace just goes. And then I start walking, you can see I walk for about 200-300 hundred metres, which I don't remember doing.

I don't think I was ever afraid because when I came to, I was surrounded by four paramedics and they'd done a great job at pulling me away from the race. And what I always think about as well is that the spectators next to me were holding up their jackets to shade me from the sun.

I came to terms with the fact that this big thing that I'd been training for and looking forward to finishing didn’t happen. I was talking about it and I just went, ‘How do you get over this?’ Because it can be bad and it can be annoying, and you can be angry about it, but what are you going to do about it. And I said, ‘I'm going to do another one.’

I just felt emotional about how well looked after I was. And because I didn't really know the extent of what was really happening to me.