OPP detachments in the north have started to issue warnings of fast moving waterways as we finally start moving into warmer weather.  The turnaround in temperatures has resulted in rapidly changing ice conditions on frozen rivers and creeks.  Police say many waterways now have air holes and open water.  They add adults venturing onto frozen lakes have to watch for thin ice because what was safe yesterday might not be safe today.  Police also want parents to remind their kids about the dangers of fast-moving waterways and that they should be avoided.  A big concern is river banks are still icy and very slippery and if someone falls in the water they might not be able to get out.