Keep in the refrigerator or if u want it REALLY cold try freezing it
Metalic cups keeps the water cold and it can be also used to keep the water hot .
Ice..
The water would have to be colder than the ice to keep it cold. That is not possible unless it is brine(salt water). Then ice at 32f could be cooled by brine at say 30f.
put them in cold water
take the ripcrd and keep it in hot water for 2-3 minutes and then take it out it would be soft and keep it in cold water and straighten it with ur hands. first straighten it and then keep it in cold water
3 to 5 days.
you just keep it in clean cold fresh water.
keep cold and ends in water
like you keep a tropical water fish only you should provide it cold water instead warm water.
You can keep your dogs' water cold outside by using an insulated water bowl, adding ice cubes to the water, or placing the water bowl in a shaded area to prevent it from heating up in the sun.
One way to keep water cold without a fridge is to use an insulated container, such as a cooler or thermos, and add ice or ice packs to help maintain the cold temperature. Placing the container in a shaded area or wrapping it in a towel can also help keep the water cold for a longer period of time.
Ice, refrigerator.