You and your friends found two different creeks to swim in. The first is crystal clear and cold. The second is slightly cloudy, but much warmer. What makes the two creeks different?

The first one is Clear and Cold, which means it's freezing, and you can see Right through the water. The second one is Slightly cloudy and warm, which means that the water is the perfect temperature, yet it's Slightly cloudy, so you don't know what's under the water for sure, so there could be sharp rocks.