Yes possibly thyroid, are you menopausal? also, perhaps an infection? No fever? the Rosacea can be caused by a variety of things.
You might want to have your thyroid checked. Often the feeling of boiling blood has to do with thyroid or hormones being way out of balance. Your body is having a hard time regulating your internal thermostat which is often thyroid. See your primary care physician and have a full thyroid panel run. Also have a full Hormone panel run. Good luck!