Typically, even if the police have a warrant to search your home or apartment, they're going to knock first before they attempt to come in. They may show you the warrant to demonstrate that you can't refuse the request, but you still open the door for them and have some idea of what's going on.
Drug overdose incidents don't have to be fatal in many cases. If a person got medical care right away, he or she may live; without care that is given quickly, the chances of passing away increase dramatically. Every minute makes the danger greater.