There is not much threat from other people in Andorra, but keep safe on mountains. Don't go too high without knowing what you are doing. See Altitude sickness for more.
Drivers are warned to avoid crossing back into France if the Spanish side of the Pyrenees has enjoyed beautiful warm sunshine all day and the road temperatures drop considerably towards the evening - there is danger of black ice from ice melt. The weather in the French Pyrenees is frequently vastly different than that of Andorra and the Spanish Pyrenees. Stay overnight if necessary, as cold morning temperatures are more apparent and less treacherous than sudden evening icing.
Andorra's official language is Catalan; however, Spanish is the dominant language of communication among people of different linguistic backgrounds. French is widely spoken, especially in Pas de la Casa. Portuguese is the native language of 13% of the population. English is widely spoken by those involved in the tourism industry.
Andorra relies on the Spanish and French postal systems; the main office for each is located in Andorra la Vella.
The French post office CORREUS FRANCESOS located at Carrer de Bonaventura Armengol AD500 Andorra la Vella, Andorra (http://maps.google.es/map...) is usually open from 8:30AM - 2:30PM Monday - Friday and Saturdays from 9:00AM - 11:59AM Tel: +376 820 408
The Spanish post office CORREUS ESPANYOLS is open from 8:30AM - 2:30PM Monday - Friday and Saturdays from 9:00AM - 1:00PM Tel: +376 820 257.
Visitors should note that since Andorra is not part of the EU/EEA, using mobile phones may be a lot more expensive than in France or Spain.