taken out of context …
this phrase that could make my head asplode…
or at least create some very unsettling mental images… 
So… probably not a good idea to discuss the lungs in the crisper?
A lot of guys in the SCA are wearing them with their armor (hidden under a surcoat) for those big, hot-weather fighting events where you might be out on the field (or in the woods) for a long time. I’ve heard of mixing just a little bit of vinegar with the water.
I’ve put gallons of red gatorade in mine, rinse with water before it dries and have never had a problem.
I use mine on my motorcycle. I can get the tube to my mouth under the full faced helmet. I have a bag that straps on the gas tank, I put the camelbak in there.
Back in the day (maybe 1996 ish) I remember reading that camelbak recommended cleaning their bladders with mouthwash – Has worked great for me ever since.
For runners they do make small, maybe 20-30oz, bladders that fit in a butt pouch. I use one when running and find it works well. Doesn’t bounce around on your back. also has two small pockets to hide energy gel packets if you’re into those things.
Wired Magazine showed a hyrdration pack made by another company, North Face maybe, that was made for winter use and featured a heated drinking tube.