You can't make this shit up.
See: https://www.ready.gov/nuclear-explosion
Go to the basement or middle of the building. Try to maintain a distance of at least six feet between yourself and people who are not part of your household. If possible, wear a mask if you’re sheltering with people who are not a part of your household. Children under two years old, people who have trouble breathing, and those who are unable to remove masks on their own should not wear them.
If you are told by authorities to evacuate to a public shelter, try to bring items that can help protect yourself and your family from COVID-19, such as hand sanitizer that contains at least 60 percent alcohol, cleaning materials, and two masks per person. Children under two years old, people who have trouble breathing, and people who cannot remove masks on their own should not wear them.
Review the CDC’s guidelines for “Going to a Public Disaster Shelter During the COVID-19 Pandemic." https://www.cdc.gov/disasters/hurricanes/covid-19/public-disaster-shelter-during-covid.html
... and be aware of Climate Change and possible Sea Level Rise too.
While in your nuclear shelter... don't forget to recycle and to never use plastic straws.
Good point, probably wise to bring some flotation devices. And also, be sure to make room for BIPOC individuals who have historically been nuked more than white people.