An enormous milkshake.
BrittanyD/Shutterstock
We fed people milkshakes containing 130g of fat to see what it did to their brains.
Shutterstock/Alex Kravtsov
Thankfully treatment has moved on from the cold sponge of the amateur era. But brain damage continues to be a serious risk in many sports.
Canadian Space Agency astronaut Chris Hadfield on the International Space Station in 2012.
NASA
New research has uncovered exactly what happens to the brain when astronauts are in space.