The Haute-Savoie prefecture has issued a red alert for air pollution in the Arve valley, signifying severe atmospheric conditions due to combustion-type pollution. Effective from December 29, new regulations include restrictions on wood heating and reduced speed limits for vehicles. The air quality has significantly declined over the weekend, affecting several local areas. Residents are urged to limit outdoor activities and maintain indoor air circulation. The pollution episode is expected to last until December 30.