You cannot please everyone when establishing a temperature in your place of employment. There will be an employee who will be hot, there will be an employee who will be cold. Some employees who can will turn the thermostat up and others will turn it down.
Source: FlickrSome employees who are constantly cold who do not play with the thermostat will quietly bring a portable electric heater to put under their desk. While this employee might become comfortable, (s)he does not know how the thermostat works and that he is making it colder for everyone else.
How a Thermostat Works
I am more tolerant than most about the temperature. I was not aware that someone went to a plumbing and heating small business website and called one of them to fix the broken thermostat or heating system. They did nothing except tell me what was wrong. It was not the heater or thermostat. It was the portable heater. It amazed me that I had to explain to the employee who brought the heater on how a thermostat works.
When you set the office thermostat to a particular temperature, say 70, the heater will go on when the temperature goes a few degrees below 70. When the temperature hits 70, then the heater turns off. When you are near the thermostat and you bring the portable heater, the office heater will never go on because the temperature will stay artificially high around thermostat. The rest of the office stays cold.
Conflicts with the thermostat will probably remain. However, portable electric heaters must be banned. It will surely add fuel to the problem.