If your tenant needs to contact you, give them a way to do so along with an emergency contact.

do you have savings and an emergency fund?  

Regardless of the market you choose, please make sure you have reliable boots on the ground (agent, contractor, handyman, bird dog) to check our potential properties and be able to respond in the event of an emergency. 

What if one has a very serious emergency and needs to sell?

I would get a HELOC in place right now, as an emergency fund.  

we have an tenant who is 36 she works two jobs and had medical expenses for an emergency room visit.

They don't do anything until a pattern of illegal calls emerges, meaning, until lots of people complain about you.The purpose behind the do not call list was to shut down the call mills using robo-dialers and calling multiple times a day or week.

Make sure you account for unforeseen costs and emergencies in your budget.Property valuation: Examine recent comparable sales (comps) in the neighborhood to ascertain the duplex's fair market worth.

A few months later, tenant calls S8 for an emergency inspection and the newbie investor gets a long & expensive list of needed repairs to avoid rent abatement.

I do not have warranty policy's on my small portfolio of rentals because I replace anything that is 10 years old or older and use Lachel to take care of emergency calls.