why is my car is sizzling hot and the temperature gage is high after I put coolant on 1996 Mitsubishi 3000GT SL

I put coolant in about a week ago and now and somewhere one of the small hoses seems to be steaming hot and then I check the coolant and it was empty? why did the coolant after one week it went empty? I do not think that is normal it should last a lot longer than a week don't you think?
I did not know what model to pick because my car is a Mitsubishi Magna 1996.

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1 answer
pressure test cooling system to find leak and repair as necessary