How would you handle a planet where everything is toxic and poisonous, including food and water?

This is a bit of a weird one, I know. This would be a survival type story, where characters need to figure out how to survive in such an environment. They could either find ways to adapt to the planet or they could leave it. Or they could try to find a middle ground. <br><br>I've seen some examples of such a planet before, but none as severe as the one I am talking about. I'm talking about a planet where water is toxic and can not be drunk. A planet where food is toxic and can not be eaten. A planet where the very air that they breathe can be poisonous to the characters, depending on where they are, and how the atmosphere changes. A planet where the weather is poisonous, where the sun and the moon's light can be poisonous. A planet where everything you can find in the wild is poisonous, including plants, animals, and rocks. <br><br>How would you go about creating a story such as this? What would be some ways to make the environment deadly, but not to the point where the characters have no hope of survival? How would you create a society such that they could live on a planet like this?