“While it may be safe to drink urine in the short term to rehydrate, the physiological response to dehydration is to conserve salt and water,” Lobo explains. “Urine production decreases and ultimately humans can develop acute kidney injury and anuria (where the kidneys fail to produce urine). Therefore, the amount of urine in the medium term will not be sufficient to maintain adequate hydration.
Adding rehydration salts without good volumes of water might help Powell replace salts and sugar, but it also risked causing other negative imbalances in his body. In extreme cases, an imbalance in salt levels can lead to seizures and same brain hemorrhage.
In his hole, Powell was cooling down but also quickly becoming more dehydrated. He remembered watching a documentary, Walking the Nile, in which travel writer Matt Power developed heatstroke while on an expedition to walk along the great river. “I remember thinking it happened really quickly,” says Powell. “So in my head I was like ‘I’m overheating, this happens to me, I get really sick.'”
Eventually, the SOS team told Powell that they could get him a helicopter, but it would take four hours. “I’m going to be dead in four hours,” he recalls thinking. “At the end of the day, I thought I’d rather die falling off a cliff than sit here,” he says. He examined the cliff face and saw a few exposed tree roots to cling to. He therefore decided to try to descend, but fell 15 feet (4.5 m), opening his nose in the process.
Part of her decision to attempt the climb may have been due to the dehydration itself. As dehydration worsens, it can affect how our brain works, disturb our mood and our ability to think clearly. the blood flow to our brain, and the the brain volume itself, reduced. Mild to moderate levels of dehydration – a loss of 2% or more of body water – can affect our short term memory, our vigilance, numeracy and coordination skills, especially when performing strenuous activities in hot environments. Some studies, mainly in elderly patients, have also shown that dehydration may play a role in delirium.