In case of decompression sickness, what should you never do?

In the case of decompression sickness, recompressing the diver underwater is extremely dangerous and should never be done. This situation is a medical emergency that requires specific treatment protocols, primarily performed in hyperbaric chambers. Recompressing the diver underwater can exacerbate their condition and lead to severe complications, including further injury or even death. The proper response to decompression sickness involves administering oxygen first aid and transporting the diver to a medical facility where they can receive the appropriate hyperbaric treatment.

Other potential responses to decompression sickness, such as monitoring vital signs or providing hydration, may have specific contexts where they could be relevant, but none replace the necessity for professional medical intervention and hyperbaric oxygen therapy. Transporting the diver should be done as quickly as possible, but not underwater.