Bit of general info.
Overheating can be caused by any number of things. It is often the result of coolant loss or a low coolant level, which is turn may be due to leaks in hoses, the radiator or the engine itself. A weak radiator cap that leaks pressure can allow coolant to escape from the system. Not getting the cooling system completely filled after changing the antifreeze can allow steam pockets to form that make the engine overheat or run hot. An electric cooling fan that fails to come on due to a faulty thermostat, relay, wiring or motor may be an overlooked cause of overheating. So too can a slipping fan clutch. Even a missing fan shroud that reduces the fan's effectiveness may be a contributing factor.
Another common cause of overheating is a faulty thermostat. When most thermostats fail, they do so in the closed position preventing the flow of coolant from the engine to the radiator. Replacing the thermostat will obviously solve the problem, but may not prevent the same thing from happening again at some point in the future. So you might want to install a "fail-safe" type of thermostat that still allows some coolant flow in the event of failure.
Less obvious causes of overheating can include a clogged radiator that is filled with sediment as a result of coolant neglect, corrosion or using excessively hard water. Incorrect ignition timing and/or a lean fuel mixture (which may be due to air leaks, low fuel pressure, etc.) can also elevate normal operating temperatures. An exhaust restriction (typically a clogged catalytic converter) can also make the engine work harder causing it to run hot.