iceages Super-cold periods Subjects in paleoclimatology Periods with the largest glaciers Periods in stark contrast to global warming Major cold spells Historic cold periods Frozen periods Colds that stick around for a long time Colds that last a long time Colds that don't go away for a long time No mere cold snaps Cooling-off periods Deep freezes, so to speak Periods in contrast to global warming Glacial periods in the Earth's history Cold spells? Very cold periods Times for deep freezes They lead to major topographical changes