When ice is covered by snow, great precautions need to be taken to determine ice thickness before starting any activity. Snow can also hide cracked, weak and open water areas. Slush is a danger sign. Slush indicates that ice is no longer freezing from the bottom. Slush also indicates weak or deteriorated ice.
Ice can change with the surrounding climate conditions.
Temperature, precipitation, wind speed, ice age and water depth and water quality are all factors that affect ice strength and thickness. Never check ice or rescue a victim of ice failure alone because you could go from rescuer to victim very quickly. Individuals should wear a flotation device and ice picks when on questionable ice. They should also carry ice picks whenever on ice, as they may never know when they may need them to pull themselves out. Everyone should have a set.