Yeah... Don't do what Brandon's saying above.
In a nutshell:
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The Process
With your beer chilled down and gelatin in hand, let’s get to the process of fining your beer:
– Get a microwave-safe glass cup. I like to use a pyrex measuring cup. Measure out 2/3 cup cold water. Any water will work, but I wouldn’t use tap water if it tastes like crap.
– Add one teaspoon of gelatin, and stir the solution. I like to use using my thermometer probe, so I can check the temperature at the same time.
– Place the water/gelatin mixture in the microwave, and begin to heat it 15-30 seconds at a time, stopping to stir the solution and check the temperature. As it heats up, you’ll notice the gelatin will begin to dissolve.
– The goal is to heat the gelatin to 150F, but not much over. If it climbs to 155 or so, that’s fine, but I’d be hesitant to go much over 170F. We’re not trying to make jello, rather just trying to pasteurize the solution.
– Give the mixture one last stir, and dump it straight into your beer. Gently swirl the fermenter or keg, and return it to your fridge or kegerator for 24-48 hours.
– If you used a keg, purge the headspace with CO2 to remove any oxygen that got mixed in.
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From:
http://www.bertusbrewery.com/2012/06/how-to-clear-your-beer-with-gelatin.html
I've been using this process for a few years now, works beautifully. No need to heat the gelatin mixture to 200f.