Indeed, while there are indeed more foreigners buying property there as they're getting priced out of other places in the peninsula and/or they're being sold a nice story, Progresso is essentially the beach town of Merida's elite who flees there during the summer as the temperature and humidity within the city becomes unbearable.

In my lease, I said I would provide heat up to 65 degrees, and any temperature higher will be responsability of the tenants through other electric sources (like space heaters).

I understand that this helps with controlling temperature and air pressure in zoned spaces and the technician also told me this helps prolong the life of the HVAC. 

Is there any thermostat I can purchase that is lockable or I can program to keep the temperature within a certain range? 

Now, there are different temperatures for a lead.

@Bruce Woodruff and @Scott Mac you have to be careful with mini splits in Chicago since the temperature can get below the operating minimum for these systems to heat.... maybe if you are using it as a supplemental heater it would be ok?

The average high temperature in July, the hottest month, is around 90 degrees Fahrenheit, while the average low temperature in January, the coldest month, is around 30 degrees Fahrenheit.

Low temperature hot water baseboards (140F supply) with a condensing boiler and split systems for A/C would probably be the best bet for balancing having the tenant pay for some utilities and not having their bill be super high.  

Aloha,I would not be relying on a Tenant's subjective opinion or statements regarding room to room temperature variances.

Main item is just making sure it is acclimated to room temperature.