You can block it. The unit won't heat or cool that room anymore though. The return air does effect supply air temp. And heat pump efficiency. With a 60 degree return air temp, the heat pump is more efficient then with a 70 degree return air temp.
We are simply getting contaminated causing otherwise healthy folks to lose the function of their kidneys and for a senior citizen who is already suffering sarcopenia this can be a death sentence because of the complexities associated with Renal Failure.
The Plague of Justinian (AD 541â542) was a pandemic that afflicted the Eastern Roman Empire, including its capital Constantinople. At its peak, 5,000 people per day in Constantinople died from it, killing half the population. From there, the plague moved east and west, becoming antiquity's most lethal known pandemic.