Footnotes

• Twitter @todd_leckie, @GreenhalghRob, @RossHemingway

• Contributors MJS, TL and RH devised the study; MJS and DW secured material funding for the study; MJS, TL and R Galloway executed the study in the field; MS drafted the manuscript; all authors critically revised and approved the final draft and take responsibility for its contents.

• Funding Research & Clinical Innovation (Royal Centre for Defence Medicine) funded the cooling pod acquisition. University of Brighton provided funding to peripheral/ancillary materiele (eg, warming blankets).

• Competing interests RH is a Director of Nereus Medical Ltd, a sports medicine consultancy which specialises in the prevention, management and rehabilitation of heat illness.

• Provenance and peer review Not commissioned; externally peer reviewed.