A method of writing in a memory device comprising a plurality of MRAM cells, each cell including a magnetic tunnel junction having a resistance that can be varied during a write operation when heated at a high threshold temperature; a plurality of word lines connecting cells along a row; and a plurality of bit lines connecting cells along a column; the method comprising supplying a bit line voltage to one of the bit lines and a word line voltage to one of the word lines for passing a heating current through the magnetic tunnel junction of a selected cell; said word line voltage is a word line overdrive voltage being higher than the core operating voltage of the cells such that the heating current has a magnitude that is high enough for heating the magnetic tunnel junction at the predetermined high threshold temperature. The memory device can be written with low power consumption.