Question

It is warmer to wear two thin layer of cloth then one layer of cloth

Answer 1

Two things layer of clothes have trapped air between them which acts as a insulator of heat.
Therefore it doesn't allow coldair to come in and hot-air to go out. Keeping you warm.
This isn't the e with a single layer..
Hope this helps

Answer 2

Answer:

During winters, we prefer wearing more layers of clothing than just one thick piece of clothing because air gets trapped in between the various clothing layers. Being a poor conductor of heat, air prevents heat loss from our body. Hence, layers of clothing keep us warmer than a single layer.