The ‘Anti-Drone’ garments are designed with a metallized fabric that protects against thermal imaging surveillance, a technology used widely by UAVs/drones. The enhanced garments are lightweight, breathable, and safe to wear. They work by using highly metallized fibers to reflect heat, thereby masking the wearer’s thermal signature.
This is as good a reason as any to revist the trusty old tinfoil hat. The theory behind the cheap, smart-looking little Faraday cage was that it would render spies impotent, blocking radio waves. Turns out it does the exact opposite.
Harvey's designs suffer from the same problem. They absolutely mask the thermal signature of the covered area. But there's more to an ambulatory human than the area covered by a hood! Anyone who's worn a raincoat and noticed the pesky wetness attacking his/her legs has learned this lesson. The anti-drone garb, as Meltzer explains, would only work if it was shaped into a full-on burqa.
Actually, that would make sense if a bunch of 'em were dropped into the areas of the world where most drone killings are occurring. But I don't think that's Harvey's goal.