Back to my hoophouse. If I put a small, plastic tunnel inside the big one, then I understand that I'll save some heat at night, but what happens in the daytime if I leave it covered?

Will the temperature inside the inner tunnel be moderated (lower daytime temp) by the doubling, or will the opposite occur (higher daytime temp in the inner tunnel)?

I *did* get an education but I don't think I paid attention the day they taught us this.

Thanks.