Hi, is it safe to put my laptop on icepacks sealed in plastic bags?

My Acer Travelmate 6293 fan is been constantly on for these last few summer months, seldom turns off. Not sure why. Maybe because it's summer? My room is not hot, laptop is on hard surface, raised with plenty of ventilation. I'm not running CPU demanding programs, just Firefox 3.0, MSN Messenger 7.5, Eudora 6.2. CPU usage is between 1%-3%. CPU core temperature is a low 26 degrees celcius. Spybot found nothing significant. Disabled bluetooth and wireless.