mjhjmtu

I have an Intel i7 laptop. While running two VirtualBox VMs and while training a neural network with TensorFlow, my KDE desktop told me with a popup that I got the following message:

Message from syslogd@kali at Nov 19 19:34:50 ...
kernel:[20173.046246] mce: [Hardware Error]: CPU 0: Machine Check: 0 Bank 0: 90000040000f0005
Message from syslogd@kali at Nov 19 19:34:50 ...
kernel:[20173.046250] mce: [Hardware Error]: TSC 121d0174df8d 
Message from syslogd@kali at Nov 19 19:34:50 ...
kernel:[20173.046253] mce: [Hardware Error]: PROCESSOR 0:306c3 TIME 1511138090 SOCKET 0 APIC 0 microcode 22
Message from syslogd@kali at Nov 19 19:34:50 ...
kernel:[20173.046256] mce: [Hardware Error]: CPU 4: Machine Check: 0 Bank 0: 90000040000f0005
Message from syslogd@kali at Nov 19 19:34:50 ...
kernel:[20173.046257] mce: [Hardware Error]: TSC 121d0174df90 
Message from syslogd@kali at Nov 19 19:34:50 ...
kernel:[20173.046259] mce: [Hardware Error]: PROCESSOR 0:306c3 TIME 1511138090 SOCKET 0 APIC 1 microcode 22

Here are the most recent line on a dmesg:

[17846.274622] vboxnetflt: 0 out of 146 packets were not sent (directed to host)
[18355.212412] vboxdrv: ffffffffc0e9e020 VMMR0.r0
[18355.449845] vboxdrv: ffffffffc0000020 VBoxDDR0.r0
[18355.489410] VBoxNetFlt: attached to 'vboxnet0' / 0a:00:27:00:00:00
[18374.760376] device vboxnet0 entered promiscuous mode
[20173.046242] mce: [Hardware Error]: Machine check events logged
[20173.046246] mce: [Hardware Error]: CPU 0: Machine Check: 0 Bank 0: 90000040000f0005
[20173.046250] mce: [Hardware Error]: TSC 121d0174df8d 
[20173.046253] mce: [Hardware Error]: PROCESSOR 0:306c3 TIME 1511138090 SOCKET 0 APIC 0 microcode 22
[20173.046254] mce: [Hardware Error]: Machine check events logged
[20173.046256] mce: [Hardware Error]: CPU 4: Machine Check: 0 Bank 0: 90000040000f0005
[20173.046257] mce: [Hardware Error]: TSC 121d0174df90 
[20173.046259] mce: [Hardware Error]: PROCESSOR 0:306c3 TIME 1511138090 SOCKET 0 APIC 1 microcode 22
[20182.505179] CPU4: Core temperature above threshold, cpu clock throttled (total events = 1)
[20182.505180] CPU0: Core temperature above threshold, cpu clock throttled (total events = 1)
[20182.505192] CPU7: Package temperature above threshold, cpu clock throttled (total events = 1)
[20182.505193] CPU3: Package temperature above threshold, cpu clock throttled (total events = 1)
[20182.505196] CPU0: Package temperature above threshold, cpu clock throttled (total events = 1)
[20182.505199] CPU5: Package temperature above threshold, cpu clock throttled (total events = 1)
[20182.505200] CPU1: Package temperature above threshold, cpu clock throttled (total events = 1)
[20182.505202] CPU2: Package temperature above threshold, cpu clock throttled (total events = 1)
[20182.505203] CPU6: Package temperature above threshold, cpu clock throttled (total events = 1)
[20182.505207] CPU4: Package temperature above threshold, cpu clock throttled (total events = 1)
[20182.506199] CPU7: Package temperature/speed normal
[20182.506200] CPU4: Core temperature/speed normal
[20182.506201] CPU3: Package temperature/speed normal
[20182.506202] CPU0: Core temperature/speed normal
[20182.506203] CPU6: Package temperature/speed normal
[20182.506214] CPU4: Package temperature/speed normal
[20182.506214] CPU0: Package temperature/speed normal
[20182.506215] CPU2: Package temperature/speed normal
[20182.506220] CPU5: Package temperature/speed normal
[20182.506221] CPU1: Package temperature/speed normal
[20254.684143] xhci_hcd 0000:00:14.0: Cannot set link state.
[20254.684148] usb usb4-port2: cannot disable (err = -32)
[20254.684154] usb 4-2: USB disconnect, device number 2
[20254.704293] sd 6:0:0:0: [sdc] Synchronizing SCSI cache
[20254.964123] sd 6:0:0:0: [sdc] Synchronize Cache(10) failed: Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
[20503.903214] i2c /dev entries driver

A few minutes later, I run the sensors-detect command with default settings, and then the sensors command from lm-sensors:

gui@debian:~$ sensors
nouveau-pci-0100
Adapter: PCI adapter
GPU core: +0.60 V (min = +0.60 V, max = +1.20 V)
temp1: -0.0°C (high = +95.0°C, hyst = +3.0°C)
 (crit = +105.0°C, hyst = +5.0°C)
 (emerg = +135.0°C, hyst = +5.0°C)

acpitz-virtual-0
Adapter: Virtual device
temp1: +69.0°C (crit = +98.0°C)

coretemp-isa-0000
Adapter: ISA adapter
Package id 0: +70.0°C (high = +84.0°C, crit = +100.0°C)
Core 0: +69.0°C (high = +84.0°C, crit = +100.0°C)
Core 1: +70.0°C (high = +84.0°C, crit = +100.0°C)
Core 2: +69.0°C (high = +84.0°C, crit = +100.0°C)
Core 3: +64.0°C (high = +84.0°C, crit = +100.0°C)

This seems to be an overheat. What would have happened if I hadn't immediately turned on a fan under the laptop? Would it have automatically stopped, or burned? How to prevent damage next time in case the fan is not running? Thanks.