The problem is that most of the heat transfer in an oven is radiant, so a transparent liquid in a transparent dish is going to get very little heat transfer. Though the air is transparent as well, it need much less heat to get to temperature than water does. One option is to use a non-transparent dish.
The emergency treatment of polycythemia (e.g., in hyperviscosity or thrombosis) is by venesection, the removal of blood from the circulation. Depending on the underlying cause, venesection may also be used on a regular basis to reduce the red blood cell count.
What is polycythemia vera? Polycythemia (say: polly-sigh-thee-me-ah) vera (PV) is a disease in which your body makes too many red blood cells. Your blood may become too thick, causing serious health problems. PV may cause shortness of breath, dizziness, itchy or flushed skin, fatigue, and headaches. Also, your hands and feet may become blue and tender. Sometimes a person with PV vera may have abnormal blood clots, which may lead to a stroke. This disease rarely occurs early in life. Most cases occur in people around 60 years of age.