Altitude should cause a problem only if you ski for an extended period at altitudes above 3000m (10,000ft).
At this height the amount of oxygen available is reduced and you may start to feel particularly tired after minimal exertion. You may also feel weak or suffer from headaches, particularly during the first few days.
Wait a few days before going to the highest point in your resort.
Skiers who stay at these altitudes for longer periods or ascend too rapidly may develop acute mountain sickness (AMS).
This starts with tiredness, headaches, nausea and dizziness, but can rapidly progress, through changes in personality and behaviour, to a life threatening condition.
If you suspect someone in your group has acute mountain sickness, you must descend immediately, as this is the only way of reversing the condition.