Video Link:

https://www.youtube.com/watch?v=gtSbJv2kSHk

Notes:

1/4in Sintra PVC vs 1/8in Sintra PVC vs 1/16in FRP Shields

Conclusion:

All 3 Boxes with shields were within 1.3°F of each other. 1/8in Sintra PVC is the most cost effective material and thickness. Also easiest to cut to shape.

Recommendation:

Use a light colored paint and/or heat shields to protect your nest boxes.

Note:

There was a question about ventilation in these boxes. There is a 1/2in high 4in long vent in the front and also a pair of vents in the upper back. See photos below.