Ok, first off, I would not be caught DEAD wearing jeans in that environment . Jeans being cotton get wet very easily. They don't dry worth a damn and they suck heat and therefore life from you like a vampire. If you are wearing them - take them off! You are better off with bare legs. The polo shirt is ok, provided it's polycotton and you have had the brains to bring an appropriate warm layer and hat with you. Paclite gortex jacket ( and trousers if you have 'em), poncho and lines for rigging ( I carry the poncho, 4 mini carabiners, tent guylines and an extra 20ft of line in the same stuff sack. calories in what ever form you fancy including an instant warm drink of some description , bottle or bladder pack of water and something to brew up in (tin cup). Head torch and a few wet fire cubes, firelighting kit and knife as well. Folding saw. The whole lot should fit comfortably in a 20L daysack. Get the poncho up. get under it. sit on your bag. brew up, consider you situation and wait for sunrise. The only thing you need to really worry about is that trees around you don't topple over and there are no widow maker branches above you. In fact you might want to consider, having checked the weather forcast ( Bright and Sunny a.m, High winds and rain moving in from the North East midafternoon or evening) not going walkabout in the first place. Woodland hills etc become very hazardous enviroments in high wind and wet conditions. Anyone who wants to live long enough to Be An Embarrassment to their Kids would do well to exercise a bit of caution and common sense in these matters. After all, you wouldn't fly a plane, without desperate need, into a storm would you? Ultimately the best way to survive a situation is not to be there.