What is a critical factor to monitor when a diver is in the recompression chamber?

Monitoring signs of decompression sickness is essential when a diver is in the recompression chamber, as it directly relates to the diver's safety and health. Decompression sickness occurs due to the formation of nitrogen bubbles in the body when a diver ascends too quickly after a dive, and the recompression chamber is utilized to treat this condition by allowing the diver to breathe pure oxygen under pressure. This process helps reduce the size of the nitrogen bubbles and facilitates their absorption back into the bloodstream.

By keeping a close watch for signs of decompression sickness, such as joint pain, fatigue, or neurological symptoms, medical personnel can intervene promptly and administer the necessary treatment. This vigilance is crucial because complications arising from inadequately treated decompression sickness can lead to serious health issues or even mortality, making it a primary concern in a controlled recompression environment.

In contrast, while factors like water temperature and psychological state may have their importance in general diving safety or well-being, they do not have the same immediate and critical implications for health as monitoring for decompression sickness does.