Outdoor Hydration Basics

Whether you’re hiking, camping, hunting, or just taking a walk through the park, it is important to hydrate properly while outdoors. To help you learn the proper hydration methods, this article covers:

  • How much water to bring
  • How to prevent improper hydration
  • Water carrying methods

How much water to bring

One of the most important considerations to make when going outdoors is how much water to bring. A good rule of thumb is to bring 1 liter of water for every two hours of hiking. However, deciding on how much water to bring depends on several factors:

Location: Geographic factors such as altitude and sun exposure will affect the amount of water you need to bring. If you will be in high altitude areas or areas with direct sun exposure, you should opt to bring more water.

Weather conditions: The outdoor weather conditions are one of the most important factors to determine the amount of water you should bring. You should bring more water if you will be somewhere where there are high temperatures or low humidity.

Activity being performed:  You may not need much water for a leisurely walk through the park. But if you will be carrying a large pack or hiking extended distances, you should bring more water. If you are going to be camping somewhere, be sure to bring enough water for cooking. Also remember to bring water for you to drink while lounging around camp.

Your fitness level: This is a personal factor. Some people simply need more water than others. While hiking with my dad in the summertime, I noticed that he drank twice the amount of water that I did. This is because he is a much larger person, and heats up much faster than I do. Every person is different. With experience, you’ll be able to fine-tune the amount of water that you bring depending on your personal consumption level.

Sources of freshwater on the trail: If you know that you will be coming across a source of freshwater on the trail, then you can take advantage of it. Some sources of freshwater include streams or lakes. You can save some weight by bringing less water than you normally would, and replenishing your supply when you reach the stream or lake. Just keep in mind that not all freshwater sources are consistent. Some streams dry up during certain times of the year. Other times, they can freeze over. If you are considering using sources of freshwater to drink or cook, be sure to read the section below on water filters and purification.

If you are unsure of how much water to bring, bring more than you think you need. It is bad to bring too much water, but even worse to not bring enough water.

Hiker drinking water in the mountains

Improper hydration

Now that you have a good idea of how much water to bring on the trail, let’s discuss the consequences of not hydrating properly. It is common knowledge that not drinking enough water is bad for you. However, drinking too much water can be a bad thing as well.

Below, we’ll discuss two conditions: Dehydration and Overhydration.


Dehydration occurs when your body doesn’t have as much water as it needs. This usually happens when you don’t replenish your body’s water that is lost due to sweating, breathing, urinating, etc. 

Early signs of dehydration are:

  • Thirst
  • Dry mouth
Trey displaying his Platypus bottles
Remember to pack water and stay hydrated!

If you are thirsty or have a dry mouth, then go ahead and take some sips of water to quench those feelings. This is usually enough to prevent your dehydration from advancing to a more serious issue. 

Moderate to severe dehydration are more advanced forms of dehydration. Moderate dehydration occurs when early signs of dehydration are ignored, or you lose more water than usual due to things such as excessive sweating.

Signs of moderate and severe dehydration are:

  • Cramps
  • Headaches
  • Nausea
  • Rapid heartbeat. 

If you have signs of moderate and severe dehydration, it is important to rehydrate right away. You may also need to seek medical attention.


It is well established that drinking too little water is bad. However, drinking too much water can be a bad thing as well. Hyponatremia is a condition that occurs when sodium levels in the blood become diluted to a point that causes your cells to swell. This inhibits cell function and leads to many problems. 

Some symptoms of hyponatremia are:

  • Nausea
  • Vomiting
  • Fatigue
  • Headache
  • Cramps

The symptoms of hyponatremia are very similar to the symptoms of dehydration. Because of this, overhydration can be confused with dehydration. An overhydrated person might drink even more water because they think that they are dehydrated, further exacerbating the issue. 

To prevent overhydration, it is important to replenish the sodium (electrolyte) levels in your body. Sports drinks such as Gatorade contain electrolytes to replenish those lost during hiking. There are also electrolyte mixtures that you can mix into your water to provide an instant sports drink. Even eating salty snacks such as potato chips or pretzels will help to replenish your electrolyte levels.

When going on a day hike, I like to bring one liter of sports drink as a replacement of one liter of water that I carry. For instance, if I am going on a six hour hike, I will bring one liter of sports drink and two liters of water instead of three liters of water. Of course, this is only a rule of thumb. The amounts that you carry can be modified according to your needs.

Water Carrying Methods

There are a few different methods of carrying water. Some are better than others, depending on your needs and preferences. Some people prefer traditional bottles, while others prefer using a bladder such as a CamelBak. It is often beneficial to utilize multiple methods of carrying water. For instance, a Nalgene bottle is good for mixing electrolyte solutions, while a collapsible bottle can fold down for storage while not in use.

  • Water Bottle: The most common type of water container is the simple water bottle. Water bottles come in all shapes and sizes. A size that you’ll probably see on the trail is the 1-Liter “Nalgene” water bottle. Water bottles are the tried and true method of carrying water. They are durable and easy to use and maintain.
  • Collapsible Water Bottle: Collapsible water bottles have become popular recently because they are easy to pack. When they are full, they are able to mold their shape in a stuffed backpack. When they are empty, they can be folded down to take up very little space. If you have ever hiked out of a trail with a pack full of empty bottles, you’ll know how annoying it can be. Collapsible water bottles get rid of that.
Two collapsible water bottles
Collapsible water bottles such as these fit nicely into a pack and take up little space when empty
  • Water Bladder: Water bladders or “CamelBaks” are designed to integrate into your backpack. They have a tube that extends outward from your pack for you to drink from. These are very nice because you never need to stop to retrieve your water bottle from your pack or open a lid when you need to drink. However, water bladders can sometimes leak. They also can be difficult to maintain since there are a few different parts and pieces.

Water Filters and Purification

A gravity water filter such as this one can filter out almost all dirt and particles

If you are going to be hiking near a stream or lake, you might be able to use them as a freshwater source. Filters are great to have along if you will have a source of freshwater available. Depending on where you are hiking, it may be necessary to filter the freshwater before drinking it. Filters are able to remove almost all dirt and particles, making the water quite clean and decent tasting. 

However, water filters do not filter small bacteria such as leptospira. It is important to know what kind of potential pathogens may lurk in your freshwater source. Making bacteria-tainted water safe to drink requires an extra step: water purification. 

There are a few different methods of water purification. The simplest method is to boil the water. Boiling the water ensures that all pathogens that lurk in your water are dead. If your chosen purification method is boiling, be sure that the water is boiling steadily for at least 1 minute (3 minutes for altitudes over 5000 feet)

Another way to disinfect water is to use purification tablets. Purification tables are very handy because they are easy to use and easy to carry. They do not weigh much and are simple to use: just drop it in a bottle of water and wait for it to dissolve. If you decide to use purification tablets, be sure to check the instructions. You will often need to wait about 30 minutes after adding the tablet before the water is safe to drink.



Trey is an avid outdoorsman and curator of Code:Outdoors. He enjoys discovering new places and learning new skills. He is an Eagle Scout and can be found both car camping and on rugged extended adventures.

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