Low Coolant Light

So I was driving on the HWY the other day (about 80 or so) in sixth gear and my low coolant light came on for about 10s, as soon as it came on I slowed down (there was nowhere to stop) and it went off. Once I was home and the car cooled down, I checked the coolant level and it was fine (just under the cold level, I added a little coolant anyway to just over the cold level). The next day I was just driving down the street, nothing crazy, just normal 45mph in 5th and the light came on again for a few seconds. I havent driven it since and it goes to the dealer for the airbag recall so I will ask them about it.

Any ideas what is going on?

Low Coolant Light