The Brevent lift takes you a little higher with beautiful down hill walks and areas to explore. You can then walk downhill to the Flegere mid station and get the lift back down. For example take the Flegere / Index lift ( 2,300 metres ) and there is a lovely walk to Lac Blanc mostly downhill with a little up hill at the end. There are fantastic walks in the Aiguilles Rouges with awesome views of the main Mont Blanc Massif. Ropes courses around the valley, great rock climbing instruction for kids at Gaillands, luges, mountain zoo down the valley, try a burger at Poco Loco in town. Spend a day or so in the valley - great family cycling with bike hire. So being aware and keeping an eye on each other is important.ДЄ suggested plan if you are hill walkers that don't want to expend too much effort that my children enjoyed ( youngest was about 7 at the time but obviously all children are different) : However, as has been stated, a small number of people can be affected. Most sightseers would be fine going up the Midi as long as they do not exert themselves too much, different story for an unacclimatised walker / climber intending walking out from the station to do a mountain route. There will be plenty of folk about and it really is a nice walk and you can get yourself a hot chocolate at the end before you head back down. If you're looking for a bit more that just walking around outside lift stations I'd suggest getting the bus up the valley to Le Tour - from here you can either walk up to the Albert Premier Hut which is a steep walk out of the valley to the top of a chair lift and then a meandering gentle path up to the hut, or get the chair lift up the hard part and walk along to the hut. If you're just planning on going up to lift stations, having a walk around and taking some pictures I wouldn't worry too much, and like you said if you or your kids are affected in a bad way get the next lift down to the valley and the symptoms should disappear.

Stay well hydrated, wear sunglasses (the stronger sun can give you a headache on its own - especially with all the snow around), eat plenty of food. I have never heard of it, which doesn't mean it is impossible, but must be rare.)Д®veryone reacts to altitude completely differently but don't let the worry stop you doing things, just be aware of it. You are highly unlikely to have any kind of significant acute altitude related problem on any of the lifts in Chamonix. If you experience symptoms you can either put up with them for half an hour or just descend until they disappear.

At the top you might well notice mild symptoms (slightly out of breath, a little dizzy, mild headache), or none. As an adult I am sure you will be fine to the midi mid station. I have no idea about young kids, I don't want to speculate, sorry. There is the Montenvers train which will take you up to look at the Mer De Glace. If you mean 'up' the mountains then you can always just walk straight up and out of the valley. I used to live in Cham and also find it difficult to adjust to altitude, so a few thoughts (not entirely comprehensive and as a caveat, I am not a doctor)

Down with the sickness midi