Electric Fire!

[ickmagnet]

About a week ago, I was halfway through an episode of Game of Thrones when I noticed a flash and a small fire coming from my reef fish tank. I rushed over and realized that the plug of my heater had basically melted right onto to the power bar Fortunately, the small blaze died itself and no damage was done (new power bar was needed).

How can I prevent this from happening again? There are only 2 koralia pumps connected to the same power bar and it is located away from the water so I am confident that it was not caused by any water damage. Currently I have not bought another heater because the summer heat and my lights are keeping the temperature in check. Eventually, I will have to get another heater. Any advice is appreciated.

Thanks