Use a wood fire
Use the Sun
You can keep food warm without electricity by using insulated containers, wrapping the food in towels or blankets, using a thermal cooker, or placing the food near a heat source like a campfire or hot water bottle.
A water heater heats and stores water for household use. It works by using a heating element or burner to warm the water inside a tank. When hot water is needed, the heater releases the heated water from the tank through pipes to faucets and appliances in the home.
By using warm water and stirring it around
No because your using warm and cold water not hot warm or cold water and green dye
Some effective methods for keeping food warm outside without electricity include using insulated containers, wrapping food in towels or blankets, placing hot food in a cooler with hot water bottles, using a portable thermal cooker, or using a portable food warmer.
Some of the American appliances that warm up include hair dryers, coffee makers, vacuum cleaners, refrigerators and curling irons.
To soften butter without a microwave, you can leave it at room temperature for about 30 minutes or cut it into small pieces to speed up the process. Placing the butter near a warm stove or in a warm water bath can also help soften it.
Slow warm up using warm (not hot)water in a hot water bottle wrapped in a towel in any case.
You can keep it warm by keeping it out in the sun. If there is no sun, than I don't know how it will it will stay warm.
To safely and effectively defrost food using warm water, place the food in a leak-proof plastic bag and submerge it in a bowl of cold water. Change the water every 30 minutes to ensure it stays warm. Do not use hot water as it can promote bacterial growth.
There are a variety of ways to clean stainless steel appliances for the kitchen. However, the most common and safe way to clean these appliances is to simply wipe them down with a cloth soaked in warm water. It is important to wipe in the direction of the polish lines to prevent spots.
The best way to do so be be to use a good thermal insulator. A thermos flask would suit this purpose.