The main thing we need to fix is the air conditioner unit.

If an Air Conditioner runs nonstop because It can't reach temperature even if it's brand new, yes it can freeze up.

An example: we had a young couple who were undergrad students, and we went in there one day to fix something, and found the air conditioner and the heater both running, like mad, each trying to outdo the other.  

Tenant units have fire standard doors to the hallway, but if they're propped open - the fire would not be contained.It's up to me to get an air conditioner if I want to be cooler, according to the landlord, but I regularly prop open my door, just like my neighbors do, in order to stay cool.  

Fish tanks, computer equipment, lighting, heating pads, portable air conditioner, electric blankets, power tools, just on and on. 

But, as unlikely as fires are, I couldn't live with myself if a tenant died because they couldn't escape out the window:https://www.amazon.com/BLACK-DECKER-BPACT08WT-Portable-Conditioner/dp/B01DLPUWL2/ref=sr_1_1?

As far as a tenant installing an air conditioner, I'm not worried about that too much as it's not a complicated process.

For cooling, we rely on seven window unit air conditioners and free-standing window units. 

Add a few window air conditioners you don’t have enough power.  

Me: "Do you mean your air conditioner isn't working?"