Antifreeze could be running out often due to a leak. It is important to inspect the radiator for small cracks or smoke.
Antifreeze keeps your coolant from freezing. It keeps your coolant more "fluid".
antifreeze does two things. It keeps the water in the radiator from freezing in the winter, and helps prevent if from boiling over and evaporating in the summer. You can run your vehicle with water alone in moderate temperatures and it will do the job. But, if you mean by "running out of antifreeze" you mean there is no liquid in the radiator, then yes, your vehicle can overheat and ruin the engine.
it keeps you warm.
Yes
( NO ) with the engine cool
Antifreeze keeps water from freezing when it is cold out. The antifreeze liquid lowers the freezing point of the water. Even when freezing (to a slurry) it does not form solid ice that can rupture the radiator. The antifreeze combines the water to form a liquid with a lower freezing point than water alone.
Anti-freeze also raises the boiling point of the water and keeps the engine running cooler and unless you live in South Florida you won't have to worry when the weather get's cooler.
Antifreeze does 2 things. First it protects your engine when the outside temperature is below freezing and the vehicle is not running. If the coolant freezes it could crack your engine block requiring a new engine. Caution: 100% antifreeze will also freeze up if it gets too cold. For best results you have to mix antifreeze and water. Check the antifreeze container for correct mixture. Antifreeze also has other things in it that keeps the water pump in good shape, prevents corrosion of the the radiator and helps transfer heat out of the engine. You need it even in hot weather.
antifreeze keeps your car from overheating, it flows thru your radiator hose, without it your motor would blow
Find where it is running out and repair the cause.
yes you can?
you can remove the therostat as long as you do not need heat. the water runs through and keeps it cool. check the water every four days it will use more.