My husband got home from work and said his ipod

It might not be.
If the device was nearly filled or was used for continued movie watching it might have simply shut down to avoid further overheating. And as with all electronic devices, direct sunlight is a sure way to overheat your device.

Allow the device to cool down and attempt to reset the ipod (center button and up on the wheel). Hopefully that should fix your problem, as your device probably went into a sort of self-defense mode before totally dying.

You might try to attach it to you computer and see if it begins to charge or shows any signs of change on the screen.