On the website Opulentitems.com a funny thing is on sale : a pillow made of heat-sensitive material, changing its color in places of touch.
The effect appears quickly and just as quickly disappears: as they say on the site, the thermal pattern lasts no more than a minute. In general, it would be funny if it were not for the price: $ 150 + shipping cost. ')
ps: it was thought - if we increase the time of resistance of the thermal pattern, then in the stories about “we were caught in a strange bed” there would be new details :)