brief pain and swelling in hips during intense movement Description:
A brief painful, hot sensation, and swelling in hips. I can refer this as "overheat" as it will disappear if I rest my leg for few seconds, or very slow pedaling. When it disappear, it means gone, entirely, no pain at all. I can tell my hips are swelling as my pants feels tighter.

When:
During intense movement such as fast or heavy pedaling. The "heat" accumulates and keep heating up and more painful if I don't rest my legs or slowing down the cadence. At peak point (which is VERY painful), I can barely move my legs.

Current condition:
height 166.5cm, weight: 105kg, maybe this pain related to obesity but most of the symptoms only appear while cycling, rarely on any other daily activities. 

This is very uncomfortable as I need to rest my leg for 5-10 seconds every now and then to let it "cool" down. Is this caused by obesity, or improper seating/pedal position ? I tried increasing/decreasing the height of my sadle without any effect. Can anyone describe what is this and is this common among cyclist ?
I'm with Batman in that you should contact a medical professional. This sounds way too serious to trust to what some random people on the internet say. However, if cost is an issue there I can make some suggestions about some things you can do to prevent some common bike-related injuries in the future (after you see a professional or did something else to get rid of it). 


Did I already say you should really see a professional? This isn't normal at all, and really sounds like something you should have checked.
Get your bike set-up properly. Go to a local bike shop to some help, or google around for something like this. Note that it is very much possible that your bike is too small or too large for you, in which case there is nothing to do but get a bike better suited to your size.
Fast or heavy pedaling? You should use your gears! Optimal pedaling frequency is around 80-100 rotations/min. Lower than 60 puts a serious strain on your joints. If you can actually produce useful force above 140 I applaud you but that speed is also inefficient and strenuous. Try to change gears more often, if you need to go lower or higher than you can regularly then get lighter and/or heavier gears.
Did you recently increase the amount of cycling you do? Though mostly a low-impact sport cycling can still cause injuries, and you should increase your workload slowly over several weeks or months depending on your age.
Seriously, go see a professional.