while I agree that the crowded conditions of a shelter can be a cause for some extra caution it also depends upon where that shelter is and who the co-habitants are. An urban shelter where I an thrown in with strangers from all walks of life from many socio-economic stations would be very different from a shelter in a suburban / rural highschool where I know 50-70% of the families there. My most common scenarios are the later. Further, as an active, emergency communications certified, HAM I will probably be in the corner with a bunch of other HAM's taking shift duty with them. Those awake and on-duty will be aware of what is going on and those off duty must get as much sleep as possible in order to be fresh for their duty time. Being involved in the ongoing effort to maintain civilization has it's perks, such as having trusted comrades working with you to protect a common good - rather than being thrust, on your own, into a situation where all others are considered threatening.