I had a really good question from a blog reader today about why I recommend the Cossack design.

Look at the instructions for DIY light hat devices, and the photos of both devices, and you'll see that Eliza is all enclosed, with a few holes at the top, and is lined with reflective foil, whereas Cossack is very open, lots of ventilation, no reflective foil.

Remember that Eliza, and the bucket idea, came out of the very first days of playing around with LED strips, trying to figure out how to make them behave. They didn't like it. They refused to stick and stay stuck, which is why I ended up lining the Eliza bucket with foil insulation, and then cutting small bits of foil tape to stick the LED strip down. Why did I do that? Because we had not long finished installing underfloor insulation, and I was well-acquainted with the stuff and especially with that excellent foil tape. Once stuck, it sure didn't want to come unstuck. So it was my solution at the the time, and better than nothing.

But, the downside was that Eliza was a fiddly pain to make. Even worse, it was uncomfortable for many people with PD to wear because it got hot. Comfort is vital, and people with PD are very sensitive to slight increases in temperature.

Michael, engineer extraordinaire, came up with a far better solution using the mesh, and the whole process of putting together a Cossack is SO much easier, it looks better, it fits better, it is much cooler to wear. It is a total winner.