Point emphasized was that everything you say about cars seems to be about Cars in Canada and not Pakistan.
Are cars different in Pakistan? Is Pakistan using a different technology? I don't think so.
Now whether you call it Engine coolant Temperature Sensor or something else. We call it Automatic Radiator Fan switch here in Pakistan.
That’s what I found funny about your post.!!!
You can call it a donkey switch and it still wouldn't matter...
Why do you call it Automatic Radiator Switch? ECT does not directly turn on the fans... ECT signals the computer and the computer turns on the fans.
Leave it man! We are in Pakistan. We can call it whatever we want! In Canada, It may be a crime to call it by some other name, but you know we have democracy here
Who is fighting? Not me... No it's not a crime to call ECT something else but we like to keep things proper way... and about democracy... I don't want to get in to any political talk but
Yes don't you think Pakistan should be awarded with some kind of medal for electing a president democratic way... even though he is corrupt... known as Mr. 10% and now some people call him Mr. 100%.
but no one objected him being president...Yes... this is democracy... 
Now here is why you shouldn't call ECT a "Automatic Radiator Switch"
ECT's job is not only to control Radiator fans... It does a lot more than that...
The ECT sensor is very important. Its input is used to regulate many engine functions such as activating and deactivating the early fuel evaporation, EGR, canister purge, and TCC systems controlling the open- and closed-loop feedback modes of the system.
A defective ECT sensor may cause some of the following problems:
Hard engine starting
Rich or lean air/fuel ratio
Improper operation of emission devices
Reduced fuel economy
Improper converter clutch lockup
Hesitation on acceleration
Engine stalling
And I just want to say this.. Man Please if you don't know how to flush the cooling system yourself.. Don't advise others... It can cause overheating.
After lunch I'll explain why it can lead to overheating and proper way to flush the cooling system.