The Untrustworthy Shadow Guide
Since Jake's arrival on the real island and the beginning of his third trial, only a few hours had really passed and it was still only past noon. The sun was at its zenith and without his tanned skin, he would have been facing the risk of dangerous sunstrokes.
The temperatures on the island in the middle of the day were indeed scorching and very few animals were willing to leave the jungle with milder temperatures. Besides the influence of the three mysterious minerals affecting the mind in different ways at night, the quietness of the fauna during the day could also be attributed to this unbearable heat.
For the time being, Jake had nothing to fear. He was surely one of the few participants originally human to be totally indifferent to the radiation emitted by this artificial sun. For the other Earthlings, it was their high Consitution and Vitality that allowed them to endure this hostile climate.