For some reason my previous attempt to answer seems not to have gone through! Second try! To start with I would replace the "c" with a "k" because words beginning with "c" are rare in German. So "Klimafieber" - pure and simply "Climate fever" or "Climatic fever". He caught something which gave him a fever and he died - probably because the people around him did not know the best thing to do. Diagnosis was very primitive at that time - the Captain would have to register the death and would have no idea of what it really was, "fever" was an almost essential accompaniment to any sort of travel - could even have been something quite simple but they let him get dehydrated. I do not think you will get any closer than that - he had a "fever" and died. Hope this is helpful.