I have a 98 honda accord, and while driving the car home from work I notice the air conditioner stop blowing cold air and starting blowing rather warm air then I notice the temperature hand was on the "H" (hot) so I pulled over and steam was coming from under the hood. So I waited awhile and add water to the radiator then after 15-30 minutes it was around normal again. This has happen twice, once with me and once with my mother-in-law.