Helmets were worn by most NFL players when the league started in 1920, however they were not made mandatory until 1943. The NCAA did not require players to wear helmets until 1939.
Baseball helmets became popular in the 1950s although wearing a helmet at bat was not made a mandatory rule until 1971.
Evgeni Malkin and a whole lot more.
Back in the early 40's when T.V.'s came out
At the start of a hockey game, six players are on the ice for each team: a center, a left winger, a right winger, two defensemen, and a goaltender.
Obviously, helmets are worn for protection as hockey is a very dangerous game to play. Hockey is a body contact sport, along with flying pucks, raised sticks, sharp skate blades, etc. When the first helmets were made and worn I have no idea at this time. Maybe someone reading this will know more information.
Kyle Quincey, Deron Quint, Stephane Quintal
Hank Aaron, Harmon Killebrew and Harvey Haddix are famous baseball players. Gordie Howe and Bobby Hull are famous hockey players.
They started wearing helmets when a guy got tackled and he got an injury so they decided to make an invention that protects your head from you getting hurt. It's made of hard steel so when you bump into somebody you don't get an injury. That's when they started making helmets......
If you mean helmets, as in American football helmets, the answer is no. This is because they would simply be too heavy! American footballers can wear them because the game is stop/start and one player doesnt play a full game because they have attacking/defending teams. If you mean a scrum-cap, then yes rugby players probably should, if they play in the scrum, it will stop their ears from becoming deformed, but many players outside of the scrum wear them too.