But are they really a good idea? Some scientists say it will soon be possible to connect a sick person’s head to a healthy body.
2030 forecast: human head transplants
Trump card: By 2030, could Donald Trump have extended his lifespan (and the life of his presidency) by transplanting his head onto the body of a much younger American? Glossary
Ambulance - A vehicle that takes medics to unwell or injured people and brings them to hospital.
Operation - Camac Energy had hired a Chinese company to carry out a seismic survey through the ancient forest, which is home to at least ten endangered species. It would have involved laying hundreds of explosive charges every 60m (200ft) to send shockwaves up to 4km underground. But the elephants there communicate by sending subsonic vibrations through the ground.
Science fiction - Stories based on major scientific or technological changes.
Surgeon - Somebody who carries out operations on unwell people.
Transplants - When a part of one individual's body is given to another in surgery.
Unethical - Not morally right.
Experiments - Tests carried out, often by scientists, to find out whether an idea is true.
China - A country in East Asia, home to 1.4 billion people.
Strict - Harsh and believing that rules must be followed exactly.
Spinal cord - The bundle of nerves enclosed in the spine, connecting parts of the body to the brain.
Patient - Somebody being treated by a doctor.
Constant - Never stopping.