In some locations there may be detailed planning and preparation for protection in case of a crisis or emergency during which a nuclear attack might take place. In those localities, many of the tasks described here will already be done before the crisis happens. Even in those localities where as much has been done as possible before a crisis, there will still be some tasks that should be done soon after a crisis occurs.
It may not be possible to do all these tasks before fallout arrives at the bomb shelter or fallout shelter, and in that case, those tasks that can be done inside the bomb shelter can be done later while fallout is arriving. Those tasks that require trips outside the bomb shelter will have to be postponed or forgotten if they are not completed by the time fallout begins to arrive, unless special circumstances of extreme urgency or very low risk make the trips worthwhile.
No one who is in a bomb shelter when fallout begins to arrive should leave the bomb shelter except under special circumstances of extreme urgency or very low risk.
If a crisis develops quickly, leading to a nuclear attack on short notice, pre-designated Cold War bomb shelters in the communities where people live would be used. In this case, there probably would not be time to do some tasks before fallout arrives, such as checking the dosimeters for leakage or improving the radiation safety of your bomb shelter.
On the other hand, you may know many of the people in the bomb shelter and may have an idea who might be able to help with radiation monitoring and other tasks. You may also know where useful and vital supplies are located. Furthermore, you may be familiar with the bomb shelter and will not need to spend much time checking it out.
If a crisis develops gradually, there may be time for people in high-risk areas, areas which might be targets, to relocate to areas of lower risk. In this case, people who relocate may set up housekeeping in or near the bomb shelter they would use if it became necessary.
There would probably be time to work out an organization of the bomb shelter population, check out the bomb shelter, get supplies for maintaining radiation records, stockpile materials for possible use as emergency shielding, and to leak-check the dosimeters.