I know it sounds horrible but no medical attention either. Nothing. If the risks are higher people will think twice about it.

Even if you start shooting illegal immigrants on the streets, there will be people, who would risk that.
Kewp is right, the solution is not to punish the immigrants, but to remove the incentive for them to come here. If they can’t find jobs here, why would they even bother? People who hire illegal immigrants are much easier target for law enforcement. I bet most people will avoid paying for illegal labor, if they knew they could actually go to jail for it.