Polka-dot trees

Visiting Aix en Provence, I found that many of the trees have been wrapped in red fabric (with white spots).  Was this frost protection?

Aix-en-Provence, joining Marseille's year as City of Culture

No, apparently Aix is joining in with Marseilles which is currently the European City of Culture. This photo was taken in the evening sun. It was 10 degrees C, which is warmer than it was at home.