About a week
One gallon of water in the summer would last a person about one day in a hot desert.
If people have the proper clothing, shelter, tools, food and water they can live indefinitely in the desert. I have lived more than 40 years in the Chihuahuan Desert.
That would be the Arabian desert.
Many life forms that are built to adapt to the harsh dry climates of the desert such as...... -cactus -camels -coyotes -lizards -snakes -armadillos -ferns those are just a few, but there are much more
It varies. You could have a heart attack or get bit by a poisonous snake right when you get there (an example) or if you have no food or water you would last about 14 days (more or less depending on weather, survival skills and luck).
camels can last for days with out drinking water.
Marble is attacked by carbonic acid - carbon dioxide dissolved in water. The desert has little rainfall so chemical weathering occurs at a very slow rate.
In a dry desert
A person who plans to spend some time in the Atacama Desert away from any civilization would need to bring enough water and food to last the duration of the stay as well as shelter and warm clothing as the nights get rather chilly there. Visitors should also bring sufficient gasoline as there are few places to purchase it in the desert. A good first aid kit should also be included.
It rains in the desert, just not very often. So desert plants make every little bit if water that they get last until it rains again.
Camels are just one of the many animals that live in the desert. They can last long periods of time without drinking water.
u would need water, food, air, other people, and last of all, everything we have on earth!