Does the in flight fuel temp indicate prominently all the time?
On the upper EICAS screen in the lower right hand corner the fuel temperature is displayed below the fuel quantity indication. TAT is displayed in the top right corner. Display is always on.
Fuel freeze point is entered manually on the PERF INIT page of the FMC. In BA it defaults to -40°C but is overwritten as appropriate. This figure is used by the aeroplane systems to generate the FUEL TEMP LOW warning should the fuel temperature reach withing 3°C of the entered value.