Why is a tank filled with water a better conductor of thermal energy than a winter jacket?

A tank filled with water is a better conductor of thermal energy than a winter jacket because water has a higher thermal conductivity compared to the insulating materials in the jacket. This means that heat can transfer more easily and quickly through water, leading to faster temperature changes. In contrast, the materials in a winter jacket are designed to trap heat and reduce heat transfer, making it a poor conductor of thermal energy.