May or may not be life threatening.
No, not necessarily such an attack may be life treatening. However if the cold
and virus occurs with in a short interval, then may be yes because the indl`s immunity is already compromised by the attack of viral pl effusion, treatment in ICU
In general, among elderlies, immunity is already compromised to some extent and any cold or viral infection can lead to superadded bacterial infection which if goes down to the lungs may cause pneumonia
which at times can prove very dangerous and even life threatening.