Ruud Van Wijk + 4000m | Mont BlancTiel5/527-10-2018We have not been bothered by symptoms of altitude sickness while we have gone from 2500m in one day, via an altitude of 4400m to 3800m (Titicaca more), and then stayed at an average height of 3500m for about 10 days. Excellent result achieved with the height tent. We have seen enough people around us who were bothered by it for a few days and / or needed oxygen and pills. We experienced the Altitude Dream service as excellent. Thanks for the service and the advice, we have benefited a lot from it. Greetings, Ruud and Claire