This depends on a two factors: your stamina and the other players that pass you.
When you pass out, you are able to get up immediately in exchange for Favours. You can also choose to wait until your stamina has recovered. If you choose to wait, your stamina will slowly recover but items will gradually fall out of your bag and people who pass you can take them. Your clothing and the items in your pockets will not be taken, so you can protect your valuables!