I used to sous vide steak in college with just some hot water and my roommate's six-pack cooler. Water should be no more than 5F warmer than the cook temp. For a medium rare steak, cook temp is 129F so get close that. Salt the steak no more than an hour before you start. Steak goes into a Ziploc bag, submerge it up to the zipper to let water pressure force out the air and then seal it shut. Close the lid and come back in an hour, two hours if it's a thicker steak. Take it out of the bag, blot it with a paper towel, apply some steak seasoning, and toss it on a pan at the hottest temperature you can make it. Wait 3 minutes and flip, wait another 3 minutes and serve immediately. Toss a pat of butter on top while in the pan if you're a hedonist.

Only prerequisites are a cheap kitchen thermometer, a ziploc gallon bag, and a cheap cooler. Everything is available at your typical supermarket or even goodwill. This is a very hands off cooking method and requires no experimentation, just follow the recipe and you get a perfect steak every time.

The key is that a cooler holds hot things just as well as cold things but without a circulator and heater to keep the water warm, you're at the mercy of the cooler's R-value. The water will eventually get too cold to effectively cook the meat so you're limited in the length of time you can sous vide. Doing a 24 hour chuck roast is simply not going to work unless you're refilling the cooler every couple hours.