The second law of thermodynamics has a principle of heat energy travels from higher temperature to lower temperature. This happens when we put our feet into the water. The natural heat of our body will travel to the water, thus we feel cold as the heat on our body travels to the lower temperature of water.
The second law of thermodynamics describes the flow of heat. Heat flows from an object at higher temperature to the body at colder temperature. It does not flow in the opposite direction.
When you put your feet into the water. The heat from our feet will get transferred to the water. That's why feet gets cold but not get hot when you put them into the water.
The thin atmosphere of Mars is thought to be due to the planet's lack of a magnetic field, which has allowed the Solar wind to blow away much of the gas the planet once had. Venus, despite still having a thick atmosphere of CO2, surprisingly has a similar problem
