If it happens during a fight, you finish the fight.

Same with kicks, your foot can go numb, but you can still kick.
After the fight is finished who knows how you will feel.

Believed the question to be do a boxers hands fall asleep during a fight.
I do not think this is the case.
However you hit something hard enough your knuckles/hand will go numb, this is the case even with gloves.

Not every case of numbness or injury is the same.
If you injured your hand you can not say it is the same with every individual on the planet.