Why do I have to keep the defrost on all the time so the engine won't overheat.

What is your question?

If I turn defrost off the engine overheats even though I have plenty of antifreeze/engine coolant in the car.Also,antifreeze leaks from both sides of the radiator hose,it leaks onto the engine and the ground but there is no hole in the radiator hose.Perhaps the hose should be cut down and tightened?If the defrost is not constantly on the temp gauge goes in the red and smoke comes from under the hood.Thank you.