How do ice blocks retain heat inside the igloo?

Ice blocks in an igloo retain heat through their unique structure and properties. The ice itself is a poor conductor of heat, which minimizes heat loss from the interior. Additionally, the air trapped in the ice's crystalline structure acts as an insulator, further slowing down heat transfer. As a result, even though the exterior may be cold, the interior of the igloo can remain relatively warm due to body heat and the insulation provided by the ice blocks.