Bad effects of coiling electrical cables
In the article that you linked to, it says in one of the answers,


  The most notorious feature of loaded coiled cables is that they potentially generate a lot of heat in a tight space. In most cases it's not an issue, but at high load with little cooling such a coil could be a fire hazard.


And I actually have first hand experience with this. There was this extension cord (50 or 100 feet) that was wrapped around a spool, which I needed to power a small room heater. Still it was a 1500W heater which draws over half of what the outlet could deliver. Which means that it easily qualifies as a high load.

Lucky ending to the story: I could smell the insulation melting which led me to discover the danger and pulled the plug before it caught fire!

(I would have posted as a comment, but my rep &lt; 50  Thought the OP really should have this info)