Laptop Heat

How do you protect an outdoor laptop? I have a laptop computer that will be turned on 24/7 on the roof of my building (I won't go into the why). Anyone know the best approach to shield this laptop from the elements? (ie, rain and heat). I live in los Angeles so it doesn't rain that much, although I'm concerned the summer heat might cook the laptop. Any ideas? I'm thinking about putting it in a cooler of some sort, but I'm not sure if there's enough ventilation. I'm also concerned about rain.