even if ...,...cannot

not ... at all

sub-zero

air temperature, atmospheric temperature, ambient temperature

very, exceedingly, awfully / (before a negative form) not at all, at all, by no means

the way in which something is tightly packed or close together without gaps

to go out

going out

(rare, archaic) wondrous, miraculous, splendid, sublime / (rare, archaic) dignified, solemn, stern, noble, refined / (rare, archaic) beautiful, pretty

stern, grave, forbidding; dignified, stately / strict, unforgiving / tight, close, without gaps / harsh, tough, extreme, severe, hard to withstand (said of natural phenomena)