Serious Eats - seriouseats.com

This will never be able to maintain a proper temperature in the way that an immersion heater and circulator will. Not only can this cause inferior results, but is setting people up to get food poisoning if the food doesn't come to temp in the middle.

Check out the post by Seattle Food Geek above for a more accurate and reliable method.

Also, I spoke with Ziploc, and they indicated that, while their products don't contain any known harmful compounds and are food safe, they are meant for STORAGE and are not meant to be used in hot water.

As far as using a cooler to store hot liquids in, you might want to check with your manufacturer to see if you should even put hot liquids in it uncontained.

I canoe down the river in my bacon boat with the wind not flowing though my hair because the bacon grease is holding it down smoothly. It is tranquil even as the beaver chews on the delicious bacon hull. Since my bacon boat is now taking on water I decide to pitch my bacon tent and curl up in my bacon sleeping bag which is glorious even when a hungry bear is attempting to rip my impetuous bacon tent apart. In the morning after my bacon bath I set forth and discover how Noah got all the animals on the arc. He took a bacon bath my friend. The animals from all over love you and want to be your friend. Be free and enjoy its greasy goodness.