Bobsled The driver wears a visor, but the other sledders often remove it — there’s no need to see with your head tucked down.

Snowboarding At the women’s slopestyle final in Sochi, the Czech snowboarder Sarka Pancochova crashed so violently that her helmet split apart. She was not seriously injured.

Hockey Goalies often customize their masks, but advertising and propaganda is prohibited on Olympic equipment. Text from the United States Constitution had to be removed from the mask of the American goalie Jessie Vetter in order to comply with I.O.C. rules.

Short-Track Speedskating Helmets are required for short-track speedskating, an event that is sometimes compared to roller derby. In long-track, skaters move in lanes, and there is less risk of injury; athletes wear an aerodynamic hood.

They Aren’t From France At the 1976 Innsbruck Games, the West German team arrived with innovative “conehead” helmets. The aerodynamic headgear helped the team win three medals. Similar helmets were outlawed in subsequent Olympics.

Luge Sliders fight G-forces as they round turns. When athletes say they “lost their head” during a run, it means they were struggling to keep their neck aligned under the pressure.

Biathlon A hat comes in handy. Biathlon races are canceled for cold only when temperatures reach minus 20 degrees Celsius.

Alpine Skiing Ski helmets are designed to be lightweight and low-profile.

Boots

Bobsled The sprint at the start determines the speed of the sled. (Former track and field stars often make good pushers.) Spikes on the toes give traction on the ice.

Biathlon Only the toe of the boot attaches to the ski. The free heel allows athletes to take full strides across the snow.

Luge Sliders lead with their feet. The streamlined shape forces the toes into proper position.

AP Photo/David Longstreath Booties Make the Man At the 1998 Nagano Games, the United States and Canadian teams lodged a complaint against Georg Hackl, a German luger known as the “speeding weisswurst” (white sausage). Hackl, the favorite and winner of two previous gold medals, was wearing a pair of new aerodynamic boots designed to improve his time. Officials rejected the teams’ protest, and Hackl won a third gold.

Curling Curlers glide behind the stones they send across the ice. The bottom of one shoe is covered with teflon to help them slide.

Figure Skating Athletes have been undone by even the simplest technology. At the 1994 Olympics, Tonya Harding interrupted her free skate program in order to fix a shoelace. She was granted a reskate, but placed eighth.

Hockey The padding inside a hockey boot may take a long time to break in. To speed up the process, new skates are baked in an oven and the warm boot is molded to the player’s foot.

Short-Track Speedskating Skaters lean deeply into their turns. The skate’s blades are set off from the center of the sole in order to compensate for the angle of the body.

Long-Track Speedskating Long-track racers use a “clap skate.” The mechanism allows athletes to push through the toe, gaining more leverage from each stride.

Ski Jumping A jumper’s body is nearly horizontal in midflight. Boots are flexible in front to allow for a big lean forward. The high back helps the jumper stick the difficult landing.

Snowboarding Hard boots help racers maintain control while carving down a slope.