Why Laptops sometimes not shutting down when Lid closed? Red-hot laptop from bag, why

I have had all kind of laptops such as Lenovo, IBM Thinkpad, Acer, Apple and many others — with different operating systems. I have had this kind of problem with all of them: when I close the lid — I think it closed the CPU etc and I put it to the bag — the computer red-hot when I open it up from the bag. What kind of things can cause this and how can I be sure the computer does not start up in my bag or that it does not run when the lid is closed?

• My friend broke the memory -chip of his Macbook in this kind of circumstance.
• I have killed the motherboards in Lenovo Thinkpads and IBMs, getting kernel-panics and odd behaviour after this kind of circumstances

How can I avoid this behaviour? Does there exist laptops with instant-freeze so I can be sure the laptop does not get broken if I close the lid? Or is the only way to be sure the computer is not-running to shut it down?

Helper questions

1. Is this a design -problem?

2. Why is hardware/software not designed to be instant-kill-me-instant-relive-with-lid -ideology?

3. I can understand some limits to transferring information and caching things — taking time — but why not to have or at least try to have an instant mode to kill the
   computer after closing the lid so that the computer won't heat up even
   by accident after closing the lid?

Perhaps related

1. [OS-agnostic] Power on laptop without opening lid

2. [OS-related] Laptop not powering down when lid is closed, but when lid is opened

3. [OS-agnostic] Is there any way to execute something when closing the laptop's lid?

P.s. I am looking for a hardware-based/OS-independent solution to shut down or somehow freeze the computer because it looks like almost all laptops tend to have this problem, particularly when they become older.