A common cause of breakdowns is overheating, especially during summertime. Your cooling system should be completely flushed and refilled as recommended in your owner's manual. The level, condition, and concentration of the coolant should be checked periodically. (A 50/50 mix of anti-freeze and water is usually recommended.)
If your car overheats -- or if you are doing regular maintenance at home -- never remove the radiator cap until the engine has thoroughly cooled! A professional should check the tightness and condition of drive belts, clamps, and hoses.