First you will have to worry about your water supplies. Than about exposure and than food. All of the above will have to be obtainded in the different way depending on your location. Place were you are stranded will provide you with everything you need assuming that you know how to benefit from the environment. You basic kit would provide you with all necessities such as fire (assuming there is wood) or food(river/forrest animals). The thing is that you mentioned Arctic regions where obtaining food or warmth will be very hard, or desert where water is almost non existant. Also the other issue that you have to thing about is your main goal. Is it trying to survive (just existance) or is there a point (location) that you are trying to reach. I don't think that PSK alone would be sufficient to survive for four weeks but give me my jacket and tell me to stuff my pockets with everything I can and my survival chances will skyrocket.