“Ice that is formed during a continuous, hard freeze, typical of northern climates, is much stronger than ice formed during temperatures that repeatedly fluctuate above and below the freezing mark. Ice that forms where water levels change frequently, or where the water is moving, such as storm water ponds, rivers, and streams is especially dangerous because its thickness will vary with the conditions and may contain cracks.”
“Should an individual or animal fall into icy waters, moderate to severe hypothermia can occur in less than 10 minutes. The window of opportunity for a successful rescue closes rapidly beyond that time. Therefore, the primary challenge for rescuers is time.”