Feeling cold

I get up this morning shivering . I don't know where this chilly sensation came from. I am sick or may be the cold weather? I have also backache but i think backache is just the cause of prolong sitting with the computer yesterday and most of the time. I prepared our breakfast and did 30 minutes exercise to stretch my muscles then took a bath. I took my temperature with thermometer but it is 37.6 degrees centigrade. No !i am not sick. Thank God ! I don't have infection. The weather is just cold , There is no rain here in Manila but cloudy.