the main trick is to use two layers of IR reflective material.
one facing the heat source and one facing the IR sensor.
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the use of radiant heat barrier has been tested - not by me for this CONOP. it has the two layers. The durability is based on the material it is bonded to. The radiant heat barrier material is much tougher than the typical space blanket.
I used to play a celtic harp outdoors at various events- if the instrument changed temperature much it needed tuning again. i used a brand name tarp - ripstop with mylar laminated to it. it worked inside my car (windows cracked and parked in the shade when available) and at the venue. that's what caused me to look into the radiant heat material - it insulates from both sides. same idea is used in some insulated grocery bags.