Saturday morning the heatwave we’ve been experiencing in London was still in full swing. I was determind not to cave and be the first person to say ‘It’s too hot’. Not in April. The UK is ill prepared for hot weather. It’s ill prepared for any weather that isn’t drizzle really, but hot weather seems the worst.

Without aircon I had two options, spend my Saturday in the freezer section of a local supermarket or find some water to jump in. With news reports at every turn of riots at a Tesco, I decided that plan B may be the safer option as it had a smaller risk of being knocked out by a tin of reasonably priced baked beans.

In London’s Hyde Park sits the Serpentine. A big old lake that has a roped off swimming section. Every Christmas Day a group of hardy swimmers enter the water to race for the Peter Pan Cup. The Serpentine, I had decided, was the only thing that was going to stop me feeling like I was taking part in the Death Valley Ultra. So a plan was hatched that Lazy Boy and I would get on our bikes and cycle the 8 miles there for a swim.

When we arrived we practically threw ourselves in the lake. This was as speedy a transition from bike to swim as you’ve seen in any triathlon, ever. Unfortunately the swimming technique that followed was more iron leg than ironman. The water was cold and gave me quite a shock. While the rest of my body got used to it, my skinny little arms were pathetic and wouldn’t work properly. I’m no swimming coach but I think arms are quite important in stopping you from drowning.

After a mild panic that I was, in fact, going to drown, Lazy Boy demonstrated a key skill for surviving in water – standing up. After I’d mastered that and calmed down I began my swim. I told myself that the things floating past my face were ‘just leaves’ and kept my lips tightly shut.

I managed 50m. Enough to cool me down and tick ‘Swimming in the Serpentine’ off my things to do list and enough to confirm that I won’t be making the switch from runner to triathlete. Open water swimming isn’t my thing.