While there is no such technical term as dry hypothermia it's important to point out that people who spend time on or near water often discount the threat of hypothermia when they and their clothes are bone dry.
Many of the same symptoms are present but may be more subtle and hard to detect since the onset is slower than if someone is immersed or soaked in cold water. A mild case of dry hypothermia on deck can lead to accidents as the sailor becomes groggy or in extreme situations they can be irrational. In some mild cases the behaviors are mistaken as a poor work ethic or fatigue.
Knowing the symptoms and treatments of hypothermia is a great part of your safety plan. For a complete plan, proactive steps need to be taken to reduce the chance of prolonged exposure to very cold temperatures. Checking the cold weather kit your crew is using is a great way to assure a comfortable and safe crew while allowing sailors to learn the best tips for staying warm from each other.
A seasonal pre-check of cold weather gear should include personal items and vessel equipment. The Manila Amendments to the IMO STCW Conventions will require a much more rigorous safety equipment inspection so getting everyone in the habit of checking and logging gear condition is a good way to be sure you are in compliance when inspections start in 2017.