Are babies allowed to pass several days on a mountain with altitude more than 2000 meters?
It is not recommended for children to be at that altitude. Diluted and cold air which are normal for that altitude may be bad for the child. Yes, the air is clean but it is still too cold for them. This means that if you decide to travel to the mountain in this period of the year or once you get to the mountain take more care than usual for your baby. It is advisable to spend more time in a closed room and if you go out put on warm clothes and wipe your baby in a blanket.
Observed from the aspect of health the baby should be perfectly fine during your stay at the mountain but if there are some complication you need to seek medical help in the bigger cities.
From a doctors point of view you may provide appropriate conditions for its stay at the mountain but it is better to chose a mountain that is not “wild” and if it is possible with not that high altitude (around 1000 – recommended). If it is possible save that visit to the mountain for the summer.