The TV presenter, who is walking with Ronni Ancona, Craig David, Lorraine Kelly, Scott Mills, Olly Murs, Dermot O’Leary Kara Tointon and Peter White on the Comic Relief challenge, caught a stomach bug and didn't get any sleep on her first night in the desert.
"After a night spent more on the toilet than in my tent, it was good to get the trek underway, although I was nervous and felt unwell when I started this morning," she said.
"The rest of the team really helped me through. It has been really tough and rocky terrain so far. The rock slide was a bit of a shock and even after all the briefings we've had about snakes I didn't expect we'd come across one in the first two hours of the trek!"
Other problems the group have already faced included climbing a 4,000ft hill in 35 degree heat and a meeting with a deadly viper snake.
Speaking about their efforts so far, radio presenter White said: "I would say that today was the most physically challenging day of my entire life so far. As a blind person, trying to combine a steep climb while dodging rock slides is really tough.
"Dermot and I did a difficult bit of the climb together. I held onto his rucksack and tried not to drag him down. And this is only the first day!"
Fans of the celebrities can donate cash to rednoseday.com/trek. It was revealed last week that the group have already raised over £203,000.