1. At the end of a marathon sweat covered runners are given a shiny foil sheet to stop them cooling down too quickly. a) Suggest why the runner may cool down too quickly without the foil sheet (1) b.) Explain how the foil sheet reduces heat loss(2)

Note consider what type of heat loss is occurring1a) key word suggest Runner covered in sweat, when this evaporates it will reduce surface temperature (1)b) key word explain, remember this means it t not enough to just describe . Must provide 1 description with corresponding explanation The physical barrier reduces the movement of particles (air is trapped) reducing conduction/ evaporation (2)Alternative answer:The shiny foil surface is a reflective this reduces heat radiation/ the transfer of infa-red rays (2)