Question regarding blinds in heads up poker

What happens in this senario?

Down to two players. Little blind is 5 chips but it is the last 5 chips that player has. So he plays these and meets his blind.

Does the big blind still have to post double the amount of the little blind? or does he only have to match the small blind?

Thanks in advance

You might technically post the big blind but if the small blind wins the hand he only gets 5 of your money.

No, because the big blind covers the amount of what the small blind has left. In fact, 5 comes back to the big blind. Small blind can only win 10.