What can make the human body take longer to be cold?

Im 17 years old live in Houston,Tx and in good physical shape and everyone is freezing cold and the roads are icing over yet I dont need a jacket or anything and school is even canceled becuase of the weather yet im still able to run 3 miles with jus a longsleeve and everyone is huddled in their house, my mom is concerned there is something wrong with me and that Im geting sick? can anyone help me answer y this is happening? lol