Many things can cause extra heat.
Things to check
Make sure the fans are turning.
Ambient temperature. If you are in a hot area things run hotter. I am guessing India maybe?
Too much dust. Clean out the dust with compressed gas(air duster)
Poor case air flow. Try with the side panel off.
Your power supply is also pretty minimal for your system(but still should have enough). This can be made worse by higher temperatures.
You may be able to set a faster fan profile to keep the card more cool. I ran a 5870 in the 80's for years