Hello, A 47 yr old brother passed out while camping, he is overweight and tired. You have not mentioned any of his past medical (ailment) history. Fainting spells commonly occurs due to heat exposure, exposure to toxins, stress, fatigue, skipping meals, exhaustion, electrolyte disturbances, cardiac syncope, etc. Some medical factors may trigger fainting spells like diabetes, having lower than normal blood volume, idiopathic orthostatic hypotension, certain medications, etc. The brother is suggested to take rest, take fluids and water to compensate for the electrolyte imbalance so that he starts feeling better. Monitor his blood glucose and blood pressure. He should take nutritious food, berries, fruits, veggies, etc. He should recover after proper rehydration. If not he should be examined by a GP, get all required tests and investigations done to detect the pathology causing him symptoms so that he can be treated at the earliest. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician