Luc Roeg was actually sun-burnt in the scene where the aboriginal boy treats his back by rubbing him with fat from a wild boar. Director Nicolas Roeg thought it would make a good scene for the film so he picked up the camera and shot it.
Jenny Agutter was embarrassed when doing the scene of her swimming naked in the lake, so as many as possible of the crew were sent away. When shooting was done they returned, stripped naked, and went for a swim while Agutter watched.
Jenny Agutter's first nude scene. She said in an interview that when the director first asked her to do the full nude swimming scene, she was reluctant because she was "a very reserved 16-year old girl." But after he explained his reasons for it and that it was a very important part of the story, she agreed to do it because she trusted him. The day of filming she was extremely nervous and felt uncomfortable, but she just went for it, took all her clothes off and kept swimming while they filmed her from several angles. When she saw the final film, she agreed it was the right thing to do because it depicted the innocence of her character. However, in a 2015 interview, she had expressed a strong aversion about how shots of her nude body were taken out of context and exploited on the internet, something that was unthinkable at the time the film was made.