[gsodonis]

The purpose of the coolant reservoir is to keep air out of the radiator. When the coolant heats up, it expands. The radiator cap allows that colant to collect in the reservoir. As the coolant cools, it contracts and the radiator pulls a vacuum and draws coolant back from the reservoir.

If the reservoir is empty (your case), the radiator draws air into the system as it cools. Driving around with air in cooling system can cause hot spots and overheating as you describe. Prolonged driving in this mode can cause to cylinder head gasket failure in some cars; it really depends on the overall cooling system design.

Start with replacing the hose, fill the reservoir and refill the radiator and see if that doesn't cure the problem.