Do CamelBak Bladders Sweat? [+ Tips To Prevent It]

When I got my first CamelBak, I filled it with ice cold water and took it out for a hike on a beautiful summer day. 

But within an hour, water was dripping down my back and I was pretty sure that my brand new hydration pack was either leaking or not sealing correctly. 

I double checked that everything was tight and looked for holes, but everything seemed okay.

It couldn’t possibly just be sweating this bad, right?

Yes CamelBak bladders do sweat when the water inside them is colder than the outside air. Water vapor condenses on the outside of your CamelBak and can make your backpack (and your back) quite wet in the process.

CamelBak bladders sweat because of condensation. The cold water in your reservoir turns the water vapor in the surrounding air back to liquid, making it cling to the exterior of your reservoir. 

Sweating is most likely when the water in your reservoir is much colder than the temperature of the air outside — like a bladder full of ice water on a hot summer day. 

To prevent your CamelBak bladder from sweating, you can fill your reservoir with room temperature water (which will stop it completely), or use an insulated reservoir (which will slow down sweating and absorb any that still occurs).

I was relieved to find out that my new bladder wasn’t actually leaking. And even more relieved to learn that stopping a CamelBak from sweating isn’t really that hard to do. 

Why Do CamelBak Bladders Sweat?

When a CamelBak sweats, water isn’t actually leaking out of the reservoir. 

It’s just condensation happening on the outside of the bladder. 

Condensation occurs when a cold object cools the air surrounding it below its dew point, making the water vapor in the air turn back to liquid water. Those small droplets you see clinging to the outside of your reservoir are the result.

You may have noticed that ice water causes more condensation than refrigerated water — which is because the water is colder and able to lower the surrounding air below its dew point faster. 

I certainly notice this when my Nalgene bottle sweats at my desk and the same thing happens for my CamelBak bladder when I've put it in the freezer and it's half ice and half cold water.

You may have also noticed that room temperature water, or water that was cold but has warmed, won’t cause sweating. That’s because the temperature of the bladder has risen above the surrounding air’s dew point. 

So once the water in your CamelBak warms up and isn't cold anymore you'll notice that the sweating will likely stop completely.

How To Prevent A CamelBak Bladder From Sweating

The easiest way to stop a CamelBak bladder from sweating is to avoid putting it in conditions where sweating can occur — like full of ice cold water on hot, humid days.

Room temperature water won’t cause your CamelBak to sweat, after all. 

But it’s far from my preferred option. Hot, humid weather is generally when I want crisp, cold water the most. 

An insulated CamelBak bladder is much better for most people. They prevent sweat almost entirely, and any that still occurs will be absorbed by the outer insulated layer well before you ever notice.

And as an added bonus, your water will stay cold in your CamelBak for hours longer. This means no more lukewarm or hot water when I'm out on the trail in the middle of summer.

But if you don’t want to buy an entirely new CamelBak, you can always use a hydration pack insulator with your current bladder instead. 

While it won’t stop your bladder from sweating nearly as well as an insulated bladder, it will slow it down considerably and still absorb most sweat that does occur.