Fan keeps cutting in?

Hi,

Can anyone give me some advice regarding the fan on my 1995 Fiat punto. It seems to be cutting in far too regularly after i have only been sitting in traffic for just a few minutes. I am sure this is not normal? as i would have thought you would need to be sitting in traffic for alot longer before the fan comes on? If anyone could please offer me some advice on what i can do to sort the problem i would appreciate it. I have had a problem with my heater which now seems okay but the fan is still playing up. I am just hoping to get another years use out of the car before i look at getting something a bit newer.