I am very concerned regarding the lack of information and awareness of some travellers to the Salar de Uyuni with regard to altitude sickness. We had a chap in our four-wheel drive who got serious altitude and was coughing up blood and could not breathe. Luckily we had a doctor in our party and he recognised the symptoms of a pulmonary problem. If it had not been for his quick action in getting the chap to hospital in Santa Cruz, he would have died. He had to be flown by private plane and was on oxygen for the duration of the journey. I feel travel agents and trip organisers should ensure that travellers are given the right information to prevent this situation happening. I was well aware of the problem and was taking Diamox to avert altitude sickness.