My first thoughts on seeing Fake Ice was not it’s use in displays or for photography, though that is how they advertise the product. I think messing with that hypochondriac seems like a much better plan. Even if you can make him believe for one minute that he has lost his sense of hot/cold, it will be worth the small cost of this ice. Your choice of cubes or broken/melted ice.
Product Page ($4.70/dozen)