For £1500, you can avoid thermal imaging in style, bedecked with “metallic materials and silk.”
Truthiness quotient?
What about men?
Wouldn’t help much here in the US, where people would freak out if they saw you wearing one almost as much as if you were carrying an AK-47.
Well that looks awful.
If it’s blocking the heat from escaping, then it’s keeping in the heat, and you’re going to overheat in the summer.
If it did work, the person inside would begin to broil in their own juices. If body heat isn’t passing into the environment (where it could be detected), it would build up.
I expect this might be effective for a minute or so just after you put it on. After that, the garment would reach thermal equilibrium with your body, and show up just as well as you did before you put it on.
I have a wallet like that. It has a metallic mesh inside that prevents any of the cards inside from being scanned or the magnetic strips being corrupted.
I don’t know how good it would be for thermal imaging considering the fact that metal conducts heat and would warm up to body temp after you been wearing it for a bit.
For a tenth of that price though I know a shaman who can whip you up an anti-drone talisman. 
As I understand it, metalized fabric is just fabric impregnated or coated with powdered metal. I don’t think it’s a very effective way to reduce IR radiation. A shiny clean metal surface has very low emissivity (ability to emit IR), but powdered metal with adhesives, not so much.
Anyway, drones don’t usually target individuals with thermal IR imaging, do they? How would they identify individuals that way??
I saw a woman wearing a burqa at Kroger’s here in Little Rock last week. Nobody “freaked out” but she did draw a lot of stares.
It’s my understanding that they do. See what I suppose is an image capture here: New Eyes in the Sky: Protecting Privacy from Domestic Drone Surveillance | ACLU
Having done some work in machine vision, thermal imaging is of great use in the identification of warm-blooded creatures.
You can get a Space Blanketfor a dollar or two. Shouldn’t work just as well? It reflects 97% of radiated heat, and you can still see through it in bright light so you can even cover your eyes.
I think Saltire has it right. Wearer would be rapidly overheating and the outer layer would soon reach body temperature or higher. The heat would have to be dumped somewhere.
A better passive system would be a golf umbrella made of the same material with a vent hole at the top to vent any rising heat.
An active system would need to be based on something like Veskimos cooling vests.
The garment shown would probably work OK, at least against simple thermal imaging. They present what appears to be a thermal image (although we don’t really know) that suggests it works to a point.
The trick isn’t to stop all you body heat escaping, or indeed to radiate as little heat as possible, it is to expose clothing that is as close to ambient temperature as possible. A loose fitting garment that allows a lot of air flow between you and the cloth is a very good start. You don’t want the cloth to be lower in temperature or have substantially less radiation overall than the background - after all the point is to blend into the background. After a hot day the background might be still quite warm - indeed it might even be hotter than a human. You don’t wear black clothes to hide on a beach, a very low emissivity cloth may be as bad as being naked.
There isn’t going to be a perfect, one garment works everywhere, solution. But one that is loose fitting and has a lower than usual emissivity might well strike the right balance and produce a result that works against warm to cool backgrounds. Enough to be hard to pick on just a thermal imager. Of course the real flaw is that assumption that the UAVs only use thermal imaging. You will look a right prat in visual wavelengths wandering about in a silver suit. They may well use multi spectral imagers and use a range of enhancement and detection techniques. There is little hope of something like the OP’s linked garment working against these.
For desert locales, may I suggest the cactus suit.
They do. The sensor suite also depends on the size/payload/military requirements of the vehicle.
General purpose:
L3 Wescam
Gyro-Stabilized Electro-optic and Thermal Imaging Systems
The enormous Eurohawk, similar to the US Global Hawk (from their public [obviously] brochure, so numbers are fudged):
Near-real-time intelligence data is obtained through the use of different sensors on-board the Platform. Depending on the mission requirements. Missions range from collection of imagery data under all weather conditions, day and night, to Signal Intelligence data gathering.
The most immediate requirement in Germany is for the replacement of its existing SIGINT aircraft. The passive SIGINT sensors allow for detection and identification of electronic emitters such as radars or radios and thus provide the electronic situation in the area.
Radar pictures, generated with Synthetic Aperture Radar (SAR) provide reconnaissance results independent from weather conditions. Equipped with a Moving Target Indicator (MTI) mode, this sensor provides position and speed of moving targets.
An EO/IR sensor adds high resolution optical or thermal data to correlate with the radar data. The image quality enables users to distinguish types of vehicles, aircraft, and missiles.
Sensors:
Synthetic Aperture Radar (WAS/Spot): 1.0/0.3 M Resolution
Electro-Optical: NIIRS 6.0/6.5 (WAS/Spot) [Near InfraRed; Wide Area/Spot]
Infrared: NIIRS 5.0/5.5 (WAS/Spot)
ETA: SAR (Synthetic Aperture Radar) is for unmoving targets only.
:smack: National Interpretability Rating Scale
Wouldn’t it need to be full length to be effective? The garment looks like it only goes down as low as the waist.