In the Bible there’s the story of Daniel who was thrown in a fire pit and didn’t even get burned. That type of samadhi is illustrated by the Indian yogi in this video whom fire does not burn:

http://www.indiadivine.org/articles/464/1/The-Fire-Yogi-of-Tanjore/Page1.html

This is not the fire samadhi of Arhats, whereupon they can raise themselves into the air and transform their entire body into fire or water. The Tibetan master Gampopa once demonstrated   to a student his ability to sit in samadhi and turn himself into fire using a different fire samadhi (the equivalent water samadhi is mentioned in the Surangama sutra), and demonstration of mastery of the fire and water elements in terms of the “18 transformations of an Arhat” is something that Elijah of the Bible, Ananda and many other masters have illustrated. 

As to the ability to live  a super long life that Shakyamuni Buddha described, and also to keep living without eating  (inedia), this yogi demonstrates these principles:

http://www.indiadivine.org/articles/451/1/Rare-Footage-of-250-Year-Old-Devraha-Baba-in-Vrindavan/Page1.html

By setting his hut above the ground he doesn’t have to deal with people too much or get to close to them physically, something I mention that many masters choose. Inedia is an ability seen in saints of many taditions, including Christianity, because the saint can survive on chi alone due to his stage of cultivation.

To retain a long life this way, Taoism explains that he cannot eat but must keep his intestines clean, and Shakyamuni Buddha in the Surangama sutra explained that there were 10 ways you could accomplish this feat. Shakyamuni even asked four of his students to remain in the world using a particular  technique that is different from this type of dhyana.

Related posts:

1. The Samadhi of Ucchushma
2. Inedia in Nepal? Multi-year Samadhi
3. How to Cultivate the Samadhi of Infinite Space – a Meditation Technique
4. The Stages of Pre-First Dhyana Samadhi
5. Samadhi versus Enlightenment