And, once the temps outside aren't winter conditions anymore, heat shouldn't be an issue. 

I have a few techies tenants that moved temporarily to TX,FL, so Cal, etc (and temp may become permanent).Also, the tech companies may move their employees to WFH mode, and that doesn't ensure that their employees will stay in SF, since they don't need to.

They usually do not have first and last months rent and deposit to go somewhere  so they end up moving in with family for a temp situation.People say they will repay you but when they look for a job and it comes to them eating, being comfortable with utilities, or taking care of their kids then your rent goes to the bottom of the list.

Due to it being the middle of winter which have negative temps here, the builder could not install lawn, trees, sprinklers, etc and had those items escrowed to be installed by June 1st.

You could also reach out to temp nursing agencies about renting short term to traveling nurses.I had an "in" with the law school at the university next to the building I managed, and ended up rarely having to advertise anywhere else.  

Tenant calls and complains temp won't go below 75.  

It's easier to tell a tenant that they are in control of their hot water, and you can adjust the temp higher, or show them how to do it, if they're running out. 

If you were making a claim for the fire anyway, then you were already headed down that path, just make sure the insurance adjuster agrees that the home is temp. not inhabitable due to the lack of air conditioning so that you do get the loss of rents, and extra expenses.

Credit scores are husband 630 and Wife 437.Income-is just over 3 times rent, husband retirement benefit, wife on job 6 months temp to perm.

It could also be high occupancy and low AC temps.