trusbx: Please don't take this the wrong way, I'm just asking for my own peace of mind, but what are your qualifications? I'm not an EMR or paramedic, but I am a St John Ambulance (of Canada) instructor, qualified to teach Standard First Aid and recently qualified to teach their Wildnerness First Aid course as well. <br><br>While what you say about Acetominophen is, I believe, true in general, there are medical conditions (esp. pre-existing liver damage) in which the lethal dosage of Tylenol can be well below the 20 tablets you cited as a maximum safe dosage. (The Alberta College of Paramedics will not allow anyone below paramedic level to give any medication, even aspirin. St John Ambulance protocols allow me to give aspirin for a suspected heart attack, but not for pain relief.) Anything other than aspirin, I (technically) need permission from a doctor. (Of course, I don't usually count the number of aspirin tablets I have; so if I put the bottle down and turn my back, I have no way of knowing whether any of them were taken. :-) But I would certainly explain some of the potential side effects first. And I would never do this with a bottle of Tylenol, especially if I suspected the patient had a problem with alcoholism, for example.

Tom,<br><br>A frozen filter is bad juju. The ceramics will crack, I've also heard of problems with others. You'll note that the user manual for Katydan includes warnings to that effect. They must be pumped out after use. A damp filter isn't a problem, to best of my knowledge, only one filled with water. If the damp filter "freezes," any water warm enough to be liquid will quickly melt any ice particlestrapped in the filter, may take a bit of extra time/pressure for the first few pumps, but in my experience it's not really much of an issue. <br><br>I might as well take this opportunity to remind folks that flters that are meant to be cleaned (as opposed to replaced) should be cleaned after every trip and dried according to instructions.<br>

I wouldn't presume to speak for Doug, but I think either Chris or I can answer this from experience- they crack. Specifically, the expensive silver-laden Katadyn ceramic filter elements crack when they freeze. I think they would have to dry outside of the filter to prevent it- or maybe heat?<br><br>This might seem like a disadvantage, but I really don't think ANY sub-micron filter is going to like the formation of ice crystals one little bit- and others might fail in ways that won't let you know they're not working anymore. I'm not sure that's better.<br><br>I've always slept with water bottles in cold weather (foot of the bag), and I've included the filter (inside a plastic bag) when I was carrying one. I suppose in really cold weather, you're going to have to keep it inside your jacket somehow during the day. With my old (white!) Katadyn "Pocket" filter (way too big for a pocket) this would have been a real pain- with my new "mini" it shouldn't be a problem.

Sorry, I just checked your profile and see that you're a medical doctor. Should have done that first. Ignore me. :-)

Thanks for the answers, Doug and Presumed_Lost.<br><br>Tom

One of my former co-workers, left a bottle of OTC pain tablets that she picked up in Canada. They are called A.C.&C. Tablets. Each tablet contains:<br><br>Acetylsalicyclic Acid (asperin) 325 mg<br>Caffeine 15 mg<br>Codeine Phosphate 8 mg<br><br>This combinaiton works really well when others have failed. We have only 6 tablet left, so we guard them as if they were made of gold. It does contain asperin, so the cautions on blood thinning and alergies apply, especially in a wilderness area.<br><br>My only problem is that as a US citizen, my government doesn't trust me with this pain reliever because it contains codeine. I may have to plan a road trip up to the Canada just to make an ACC run! ;-)

A recent National Geographic Magazine issue had an article on infectious deseases in the world today. I haven't read the article yet, but I recall seeing a graph, using a color coded world atlas, showing the relative distribution of deaseases in the world today. Diharea was by the far the most common and prevelent desease.

Your post contains some incorrect information that I think is important to challenge. First of all, if I were faced with a survival situation, the absolute LAST antibiotic I would select is Zithromax (aka azithromycin). It has very limited usefullness and none that I could imagine in a survival situation. You are interested, I presume, in staph and strep coverage and drugs like Cephalexin are more suitable.<br>Secondly, there is NO question in any medical circle that aspirin should be given to a person with chest pain suspected of having a cardiac origin.<br>There is little need to carry aspirin, acetominophen, and ibuprofen. They are interchangable. I would carry ibuprofen alone.

Bill, don't get caught bringing a controlled (schedule IV) narcotic across the border!<br>Codeine is a narcotic and a controlled drug, in the same class as a lot of other addicting drugs that the govt does not trust us (anymore) to have unlimited access.

Beachdoc, Glad to see your still with us! Want a real horror of improper medication? I have encouraged many of the local equestrian community to carry a few items; whistle, matches and a small aid kit for horse and rider. I have discovered many horsemen self medicate with butazolidin, a pain killer for horses! Some of the DVMs even dismissed my concerns if it is done infrequently! This in spite of one known jocky dying from long term use. I am currently packing my own placebo; darnitoll and extra strength forgetitoll in adult proof containers ( Altoid mints, I had to find a use for some of those dumped candies.)