A thermal cooker can keep your meal hot and ready to serve for hours while you do what ever you want away from "the kitchen." You might fix lunch at breakfast time, or dinner at lunch time. Or wake up to a hot breakfast that's ready to eat.
Thermal cookers are similar (yet very different) to a cooking in a crock pot because no electricity, nor occasional stirring, is needed. The cookers outer vacuum insulation prolongs the slow cooking effect for hours once the food is sufficiently heated up. You "cook" (heat) your meal for only about ten to twenty minutes, then turn off the gas burner/heat source - adding no more heat, and your food/meal will continue to slow cook and stay hot (because of the vacuum insulation surrounding it) for four or more hours so you can have an active day outdoors, or traveling, and then enjoy a no fuss fully cooked hot meal hours later. Many recipes are available for thermal cooking. The cookers would be useful in areas with open fire restrictions...which may limit the use of dutch ovens. They seem to be popular with Australian campers.
thermal cooking - Wikipedia
How To Use A Thermal Cooker - Everyday Recipes for Magic Cooker has a good description of the benefits of using a thermal cooker (bold added):
What Is A Thermal Cooker?
Basically, a thermal cooker is a very big vacuum flask that can cook and keep warm for hours without using power. Like the Thermos, the layer of vacuum insulation in a thermal cooker helps to retain the heat in the food for many hours. The heat cooks the food slowly in the same way as a slow cooker. The thermal cooker is also popularly known as Magic Cooker.
The best thing about a thermal cooker is that it continues the cooking process without using any electricity or gas. Slow cookers consume a lot of power and tend to dry up some of the liquid in the food. Sometimes food gets burnt at the bottom of the slow cooker pot if it is left to cook for too long without being stirred.
Problems like these are not encountered in thermal cooking as the food will never dry up or get burnt. Once the food is inside the thermal cooker, there is no need to keep checking or stirring the pot. Most meat will turn out tender, moist and cooked to perfection, while the vegetables and potatoes retain their shape and texture. No wonder, the thermal cooker is called a magic cooker.
Nissan Thermal Cooker is a Crockpot Without a Cord Nissan Thermal Cooker is a Crockpot Without a Cord.
ON THE ROAD RECIPES from Australia.
If you search for "thermal cooker" at Amazon.com you will find many to choose from. Asian grocery stores may carry them too. Here's one: Thermos Nissan Thermal Cookware with good Amazon.com reviews.
Product Description
Thermal Cookware keeps food hot (or cold) for up to 6 hours without reheating. Nissans unique two-piece set of cookware offers excellent temperature and flavor retention and allows for easy transport in one self-contained unit. Perfect for rice stews soups and more (We love the Jambalaya!). Stailess Steel inner pot is for cooking and vacuum insulated outer container will keep food hot for hours without burning and scorching. We were amazed at how the vegetables retained their color thanks to the vacuum seal. 4 3/4 Quart/4.5 Liter Capacity. Perfect for transporting chili and other favorites to the tailgate party. Features a Full 5 year warranty.
I think that thermal cookers would be very handy for your own use while camping or to prepare and serve a dish at a group potluck. You could also prepare a hot meal at home to eat on the road or for your first meal at your camp site. They're a little pricy to buy the good ones. Over time they could help save time and money if you eat more "home cooked" meals...even while camping.
P. S. Thermal vacuum cookers are different from crock pots or pressure cookers.