maybe low on fluid?
or
maybe bad thermostat?
or
maybe bad water pump?
A repair manual for that vehicle would have that info.
Too high a temperature
bad water pump or thermostat. check both.
Different engines run at different temperatures. It would be best to consult your owner's manual.
bad water pump
No, the melting temperature of glass is very high. Your computer components themselves, like the motherboard, would overheat and melt long before the glass desk top did.
Turning the heat on would actually lower the engine temperature. It's a well known trick if your car starts to overheat. Having the A/C on causes a power loss to operate the compressor, which would also cause engine temperature to go up due to the hot air from the condensor going through the radiator.
at the bottom of your if it is cold or warm then it controls body temperature
If you temperature gauge is going up and down then you may have a problem with your sensor. You should take your car to a professional to ensure that you don't overheat your car.
Yes the temperature gauge will still work. If it stuck open the car will run cool. If it is stuck closed the car will overheat.
It would take longer to walk in hotter temperatures. The core body temperature rises while you exercise, and if the outside temperature is also warm, then you can overheat more quickly. If the outside temperature is cool, then you can walk at a faster pace more comfortably.
Friction