Build an index of malaria risk

I would need to construct the index by Mordecai et al. (2013), who build an index of malaria risk accounting for accurate nonlinear thermal responses of transmission risk.

Reference:
Mordecai, E. A., K. P. Paaijmans, L. R. Johnson, C. Balzer, T. Ben-Horin, E. de Moor, A. McNally, S. Pawar, S. J. Ryan, T. C. Smith, et al. (2013): “Optimal temperature for malaria transmission is dramatically lower than previously predicted,” Ecology Letters, 16(1), 22–30.