Accurate predictions for radiant heat flux are necessary for determining exposure levels to personnel and infrastructure in the event of wildfires. However, detailed physics-based calculations of radiant heat flux are complex and current modelling practice involves significant simplifications in order to make these calculations tractable. We detail current practice for the calculation of radiant heat flux from wildfires and investigate modelling improvements that could benefit practical usage. Furthermore, we demonstrate that current limitations can be circumvented by more advanced physical models using newer generations of computational hardware. Such physical models could allow highly detailed and accurate calculations of radiant heat flux leading to improved risk assessments and planning in regions affected by wildfire.