This 7-8 hours and 26 kilometers moutain stage crosses the Pyrenees at an altitude of 1400 m. It’s necessary to follow some security rules !
Even in summer, you need a polar jacket, poncho for the rain and a hat. don’t forget that in the mountains, the weather can change very quickly and in the Pyrenees you may have to face very strong winds coming from the south.
You need at least 1 liter of water (better to have 2 x 0.75 l)
If you sleep in Roncesvalles sleeping bag (no blankets up there)
Energetic food (cereal bars …) plus sandwiches.
Don’t forget your solar protection (Sun tan lotion, hat, long sleaves …) but also against the rain, always posible and strong in those mountains.
In case of emergency, dial 112, either in France or Spain.