Check that the ambient temperature is no more than 25°C where your fridge is kept.

Check ventilation around the fridge. You will need approximately 20mm either side and the top, with 100mm at the rear.

Check inner fan is going and that there is NO ice buildup on the inner rear wall

Check thermostat settings- Higher numbers are colder.  If these are set too high, they will ice up at the back and make your fridge warmer.  Setting it between 3 - 4 works the best.