starts first time runs like a dream until temp gauge hits half way normal temp then cuts out.gauge is saying temp ok but engine seems very hot (bonet could fry an egg).
you will need to check the following,
1-thearmostat. take off, put in pan of boiling water, if opens then ok.
2-water pump. check working.
3-check radiator has no damage to fins.
you could try and discard old coolant, and give car a good flushing as you check the above.