Comparison of two simulations with ﹩{N}_{\mathrm{ppc}}=16﹩ (dashed lines) and ﹩{N}_{\mathrm{ppc}}=64﹩ (solid lines), having the same physical parameters: ﹩{\beta }_{{\rm{i}}}=2,{T}_{{\rm{e}}}/{T}_{{\rm{i}}}=0.1,{\sigma }_{w}=0.1,﹩ and ﹩{m}_{{\rm{i}}}/{m}_{{\rm{e}}}=25.﹩ We present the time evolution of (a) dimensionless electron temperature, ﹩{\theta }_{e}﹩, in the upstream (magenta) and downstream (green); and (b) total electron heating fraction, ﹩{M}_{T{\rm{e}},\mathrm{tot}}﹩. The upstream and downstream regions show an increase in electron temperature as time evolves, caused by numerical heating. The impact of numerical heating is significantly reduced by employing ﹩{N}_{\mathrm{ppc}}=64.﹩ The measured value of ﹩{M}_{T{\rm{e}},\mathrm{tot}}﹩ is, however, largely unaffected by numerical heating (panel (b)).