Indeed, it was a day when some 84 relentless hours on the racecourse became too much for some to handle. A day when veteran teams pushed faster and harder than ever before, and when rookie teams learned some painful lessons about the realities of the Eco-Challenge.

Out in front, Team Salomon/Eco-Internet [go to Team Bio] hammered through the jungle, reaching PC 20, the start of the Sampan canoeing leg at 4:37 p.m. -- several hours ahead of race officials' predictions. A surging Team Spie [go to Team Bio] moved into second place, while persistent Team AussieSpirit.com [go to Team Bio], the race leaders during Leg 1, remained close behind. John Howard's dangerous Team Fairydown Fleet CookieTime [go to Team Bio], who at one point were seen trekking through the jungle without pants, lurked in fourth place.

But as leading teams began to stream out of the jungle, those towards the back of the pack struggled just to get there. A mandatory 12-noon cutoff time at PC 14, the end of the mountain bike leg and the beginning of the jungle trek, pushed desperate competitors beyond their physical limits.

The result kept Dr. Cohen and his staff in action all day.

"We were pushing for the cutoff," explained Team Northstar's [go to Team Bio] Chris Andrews, 29, one of six competitors who required emergency medical attention, warranting disqualification.

Teams unable to make the cutoff would not be allowed to continue into the jungle trekking leg unranked.

Suffering from dehydration and heatstroke, Andrews was given four liters of fluids intravenously on-site and was evacuated via helicopter to the on-course medical center. "I was nauseous as hell," explained the dejected racer, resting safely in Camp 1 several hours later. "And I couldn't drink enough water."

Even without medical emergencies, some 12 teams, including Team Playboy Extreme [go to Team Bio], Team Uruguay [go to Team Bio] and Guatemala's Team Hombres de Maiz [go to Team Bio], were unable to make it to PC 14 in time. Race organizers have mandated that in addition to being disqualified, teams unable to make the cutoff would not be allowed to continue into the jungle trekking leg unranked. Instead, they will have the option of either stopping outright or continuing on with the Sampan canoeing river leg.

This incensed and devastated several teams, who felt deprived of the most compelling portion of the course. Some disqualified teams complained openly and bitterly to Race Director Mark Burnett, claiming that the mandatory cut-off time was too harsh, while others internalized their disappointment.

Regardless, race organizers are not budging. In fact, some say that this year's regulations are generous. Cutoff times are implemented to ensure that the field doesn't get too spread out, requiring a larger medical staff and complicating logistical planning.

Disqualified teams who decide to continue on the course will backtrack from PC 14/19 to PC 18, pick up necessary gear, return to PC 14/19 and continue on to PC 20, the start of the Sampan canoe leg. All 12 DQ’d teams will spend the night at PC 14/19 tonight.