I tend to get mine in patterns sometimes I seem to be more prone to cramps than other times like if I am under the weather or sickening for a cold or flu symptoms. If I have been having a bout of cramps what works for me is to keep my calves, knees and ankles from getting too chilled wrapping with long thick socks and keeping my feet snug to stop them locking doing this for as long as I need to. Instead of having putting cold flat sheets on my bed I swap them for the fluffy flannelette kind in the colder seasons.