Polar T3 syndrome
Polar T3 syndrome is a condition found in polar explorers, caused by a decrease in levels of the thyroid hormone T3. Its effects include forgetfulness, cognitive impairment and mood disturbances. It can exhibit itself in a fugue state known as the Antarctic stare.
Effects of polar environment conditions are proposed as hypothetical causes of this syndrome.
It is regarded as one of the contributory causes of winter-over syndrome.