Vertigo is a weekly blog by Kieran Dahl covering the action sports and wilderness adventure world. Kieran is a sophomore in Davenport College.

Forty miles per hour on ice skates? Downhill? Sounds like a nightmare. To the energy-drink maker Red Bull, though, it sounded like an idea for a new extreme winter sport: Ice Cross Downhill.

In Ice Cross Downhill, skaters decked out in full hockey gear hurtle down steep ice chutes littered with rolling bumps, big jumps, steep drops and hairpin turns against three other competitors; the first person to make it to the bottom of the quarter-mile-long course wins. While the physical contact you’d see in a normal hockey game isn’t officially permitted, the narrow, windy tracks mean that high-speed crashes – involving airborne bodies, tangled limbs, and helmets bashing against mildly cushioned walls – are frequent.

The sport was born in 2000 when an Austrian hockey player, likely inebriated, stole onto a bobsled run and attempted to skate down it. A year later, Red Bull, the sponsor of numerous innovative extreme sports (including Flugtag, in which competitors try to fly homemade human-powered flying machines), launched the first Ice Cross Downhill event in Stockholm. The first track wound through Stockholm’s fish market and caused much ire among residents, but in the twenty events held in ten countries since, the tracks have been just as integrated into their urban venues, weaving among buildings, trees, and roads.

At this year’s world championships in Saint Paul, Minnesota, a two-story-high starting gate was constructed next to the Saint Paul Cathedral, while the track ran across the cathedral’s front steps and ended next to Interstate 35E.

Downhill Ice Cross events have rave-like atmospheres: bright, colorful lights illuminate the glistening ice tracks, while thumping sound systems blast lively music into the ears of the spectators. At the 2011 world championships in Quebec City, 100,000 strong were drawn to the sport’s combination of speed, aggression and skill.

Most competitors are energetic, athletic twenty-somethings who have extensive skating – usually hockey – experience. The Michael Jordan of Downhill Ice Cross, seven-time world champion Jasper Felder, is a professional bandy player, a Scandinavian sport similar to ice hockey. But not everyone is a professional athlete by trade or an aspiring Olympic speedskater. Competitors in Saint Paul included a nuclear-plant worker, members of a roller derby team, and two people whose occupations added a touch of irony to the dangerous event: an insurance agent and a chiropractor.