Overwhelming Fear and Anxiety:
The doctor would likely experience overwhelming fear and anxiety as the snake coils around his arm. This sudden and unexpected physical contact with a potentially dangerous animal would trigger a fight-or-flight response in the doctor's body. He may feel his heart racing, muscles tensing, and thoughts racing as he assesses the situation and tries to figure out how to safely remove the snake.

Shock and Disbelief:
There may also be a sense of shock and disbelief as the doctor processes what is happening. Snakes are not typically found in medical settings, so the sudden appearance of one coiling around his arm may feel surreal to the doctor. He may struggle to come to terms with the situation and find it hard to believe that this is actually occurring.

Adrenaline Rush:
The doctor's body would likely release a surge of adrenaline in response to the perceived threat of the snake. This adrenaline rush would heighten his senses, increase his heart rate, and prepare his body for action. The doctor may feel a rush of energy and focus as his body gears up to respond to the situation.

Desire to Remain Calm:
Despite the fear and adrenaline, the doctor may also have a strong desire to remain calm and composed. As a healthcare professional, he is trained to stay level-headed in stressful situations and make rational decisions. The doctor may work to control his breathing, assess the snake's behavior, and formulate a plan for safely removing it from his arm.
In conclusion, the doctor's feelings when the snake coils around his arm would likely be a mix of overwhelming fear, shock, adrenaline, and a determination to stay calm and in control of the situation.