Whenever atmospheric conditions are such that you have both the liquid and solid forms of water happening in your environment simultaneously, certain precautions should be taken if you plan or need to be outside for extended periods of time. Cold temps combined with wet conditions can create a perilous situation for those caught out in it but unprepared for it. The normal temperature of the human body is 98.6 F / 37 C. Hypothermia sets in when the temperature drops below 95 F / 35 C, a drop of only a few degrees. This drop can happen very quickly in cold wet conditions.
There haven't always been many options for tinder materials that worked well in wet conditions, available commercially. The ones that were available at outfitters during the 70s and 80s were various chemical compounds, which came with more a lot more health warnings than uses. but that is not the case these days. One of the latest ones to hit the market is Fat Rope Stick™. Fat Rope is cotton rope that has been impregnated with a proprietary high gasification compound. It is hydrophobic so doesn't absorb water, and it doesn't evaporate. It is also listed of the Fat Rope website as being non toxic.
The way the fat rope is twisted together it separates into fibers very easily. Once you have cut off what you want to use for tinder, all it takes is a slight untwisting motion to separate the rope into the three smaller sections. Then that same untwisting motion will separate each of those into 11 smaller sections. Then repeating that same untwisting motion will separate each of those pieces into individual fibers. It's simple and actually fairly intuitive just looking at the configuration of the rope.
Once it has been separated into the individual strands, it is easy to fashion it into a tinder nest, just make a pile of it and fluff up the strands. Separating the individual strands creates fuzzy fibers along them that take the sparks from a ferro rod really well, even in high humidity. I have tested the fat rope in the rain several times over the last 6 months. Sometimes starting with unopened sticks, sometimes with partial sticks left from previous outings. So far I have seen no noticeable difference between how well the new sticks work and how well the leftovers work. They both ignite equally easily.
As mentioned before, this material is hydrophobic so it will not absorb water. The fact that it will not absorb water is how it can catch the sparks from a ferro rod, ignite, and burn even in very wet environments. It is how it can burn even even when it floating on the surface of pool of very frigid water.
Because it is hydrophobic and will not adsorb water, it is a great tinder material to have along on waterborne or winter adventures. Because it would also burn in a pool of very frigid water even if you have just climbed, soaking wet and shivering, out of an bigger frigid pool of water.
As a life-long student of field craft and survival studies, I will probably always prefer to use organic materials under ideal conditions. Yet thanks to some of those studies and experiments, and some lessons learned the hard way, I can definitely appreciate the ability to create fire on command, even in the wettest of conditions.