Safety and emergencies
The TMB is a hiking trail, but it climbs above 2,500 m: the mountains remain a serious environment. Weather, snow and fatigue are the three risks to watch.
Updated
Emergency numbers
112
European emergency number, valid in France, Italy and Switzerland.
PGHM Chamonix
+33 4 50 53 16 89
Mountain rescue on the French side.
144 · 1414
Emergencies and Rega (helicopter) in Switzerland.
Save these numbers before you go. Mobile coverage is missing in places, especially in some side valleys: the nearest hut can then raise the alarm.
Storms
In summer, storms often build in the late afternoon. Start early to cross the passes before noon or 1 pm, and watch the sky: cumulus clouds towering quickly are a warning sign.
If a storm catches you: leave ridges and summits, move away from poles and metal objects, do not shelter under a lone tree, and crouch on your pack with your feet together.
Snow and snow patches
Until July, and from the first autumn snow, hard snow patches can cover the trail on north faces of the passes. A slide on a steep snow patch is one of the most common hiking accidents. If you are not equipped (poles, microspikes) or not comfortable, turn back or take the main route rather than the variant.
Good habits
- Mountain forecast the evening before and in the morning: Météo-France montagne, MétéoSuisse.
- Trail conditions: Chamoniarde · Office de Haute Montagne.
- Tell your accommodation when you expect to arrive, and leave your route with someone at home (the myTMB link is enough).
- Keep the GPX files in an app that works offline, and a charged battery.
- Get insurance covering mountain search and rescue in all three countries, and carry your European Health Insurance Card.