You are correct, of course, but in a sci-fi scenario maybe you could have a colony of fungi that move nuclear material around internally to keep it 'hot', thus 'burn it off' faster to extract energy. It might collect material from a wide area.
Hot is commonly used to mean radioactive. https://en.wikipedia.org/wiki/Hot_particle
One mode of radioactive decay is electron capture, which is absolutely impacted by temperature (just mentioning this as trivia, I meant hot-as-in-radioactive).