For over a week now the upper moors have been in a severe freeze with many of the footpaths covered in sheet ice with a layer of snow on the top.     Many of the usual approach routes such as Grindbrook and Crowden Brook  have their streams frozen and most of the flagged edge paths are treacherously icy.  The unwary walker could easily take a slip and break an ankle or leg.   Whilst most of those venturing on to the tops are well prepared and equipped there are …