Explanation:
The <u>First Law of Thermodynamics</u> states that energy cannot be created or destroyed in an isolated system. In other words, energy can be converted from one form into another, but it cannot be created nor destroyed.
<u>Conduction</u> is the transfer of energy from one molecule to another by direct contact. This transfer occurs when molecules hit against each other, which can take place in solids, liquids, and gases.
When you put your cold hands under your legs to warm your hands up, the heat energy from your legs is being transferred to your hands through conduction. However, since energy cannot be created, there is no extra heat energy that can instantaneously replace the heat created by your legs.
