It seems most of these reported glass cracks are from over heating. I'm in Canada and my S7 is the Exynos version which definately runs cooler than the SD version.
When I got my S7 I used it on the boat as a chart plotter side by side with my Sony Z5 in 30c temp and full sunlight running the Navionics app which is a battery hog. The S7 ran cooler , brighter and used less battery than the Sony , but was still hot to touch. Other than that type of hard use the S7 never gets hot.
I've read a lot of reports of S7 cracked glass linked to over heating and don't know if it can be blamed on the SD chip or recent sloppy S7 manufacturing.
In the OP's case , charging under the futon was not good as it just trapped the heat , especially if it was on fast charge.
When I got my S7 I used it on the boat as a chart plotter side by side with my Sony Z5 in 30c temp and full sunlight running the Navionics app which is a battery hog. The S7 ran cooler , brighter and used less battery than the Sony , but was still hot to touch. Other than that type of hard use the S7 never gets hot.
I've read a lot of reports of S7 cracked glass linked to over heating and don't know if it can be blamed on the SD chip or recent sloppy S7 manufacturing.
In the OP's case , charging under the futon was not good as it just trapped the heat , especially if it was on fast charge.