I understand that compost heaps have an ideal temperature for the bacteria to decompose the material into compost. Living in the changeable Great Britain, the weather can be windy, rainy, sunny and dry within a single day. 

Given this changeability, should I be trying to insulate the heap against changes in temperature and humidity? It's currently a wood construction with gaps for ventilation. What materials could I use to insulate it without suffocating the heap?