Hi. Thanks for your query. Noted your history of feeling warm and cold all the evening, Abdomen felt hard earlier under the breast, but now feeling bruised and tender. Now you have flushed face but hands and feet are cold. You are hoping that this is not flu. My suggestions: Watch for nausea, vomiting, loose stools, bloating and pain in abdomen.IF this develops, there is more chances of bacterial gastroenteritis than the viral one as you are suspecting. Hence the further treatment will depend upon the further development of symptoms, your response to the the disease process and the medication if any you take. Get the blood, stool and urine tests done. Take appropriate treatment.