Picture posting is enabled for all :)
Last year we had our lotty open day in early May and one of the allotment chaps had it filled up ready and he put quite a lot of grass clippings in it and it heated up like mad (even in May) and by open day it was steaming and he made a hollow in the top and invited folks to put their hand in to feel how hot it was. Folks were queuing up. Sad innit ;D