Many say they do, but it is reimbursement at closing which doesn't help.  

Her lease states that she should be changing the filters monthly and, in a subsequent section, that she would be liable to reimburse us promptly for damages... and service required by violating her lease rules.I feel we are within our rights to request a $75 reimbursement for the service call and have this drafted:Dear [tenant's name]:Per your lease agreement, we are enclosing a bill for $75.00 and a copy of the HVAC technician’s findings and the diagnostic call receipt for services required for a “severely clogged air filter blocking the air flow causing the AC system to freeze up”.Per your lease agreement, section 19B, you must replace air-conditioning filters monthly, which would have prevented the clogged air filter issue.

Can they get reimbursed if they buy portable units themselves or go to a hotel?

I am going to get housing involved, maybe they can help her with the deposit and get reimbursed by me when she vacates. 

I called the main office, and they informed me that there has been no flooding in the basement, no burst pipes anywhere in the building, and no roof leaks in the last few months.I offered that she pay for the assessment herself (from a reputable testing company, not a remediation company), and if it comes back positive for high levels of mold or toxic mold (because I know mold is everywhere in the air) that I will reimburse her the cost of the test and remediate the mold - if it wasn't due to tenant negligence. 

The intent of this is to reimburse for actual hardship.

Just pay the loan from your personal account and reimburse out of your business account.

When the motion lights weren't enough, I had the PM send a notice to every tenant in the building that they could install a motion light of their choosing and I'd reimburse up to $30.   

Pay the bill yourself, then reimburse yourself by charging the tenants based on a formula.

A lot of brokers get in trouble for commingling or taking temporary funds out, even if they reimburse.