He writes about it at length in The Blaze of Obscurity, as he later went to Japan to make a documentary about their game shows, and was part disappointed and part relieved to see that it was actually very well marshalled and monitored, with some serious exaggeration. The discomfort - hot sand down the pants - was entirely real but actual danger was minimal.
Most of this kind of reality show is distorted as hell. I spoke some time ago of my own indirect experience of them:
Likewise, Wheeler Dealers is entirely rigged. Try walking into a car accessories place and then offering them £300 for £500 worth of stock and see how far you get. The same applies even more with the haggling on Bargain Hunt (the producers make up the difference with the seller once the cameras move away.) It's all passable enough entertainment but in most cases not remotely real.
The honourable exception is Changing Rooms' direct descendant DIY SOS: The Big Build. That is exactly as they show it (my BIL worked on a couple of them, it works as they portray it, lots of local tradespeople and merchants giving their time and goods for a deserving cause, and the presenters all genuinely chip in.)