low grade fever and cold hands/feet

DD woke up hot to touch and very lethargic... throughout the day she hasn't eaten much and has been sucky. after she ate dinner she all of a sudden was ice cold and shivering... hands and feet were ice cold. we wrapped her up and she is back to being warm, 38C, but her hands and feet are still a little cold. her lips were starting to get a little purple, but after nursing they were red again.... she's down to sleep for the night but... I was thinking teething, but now they cold hands and feet has me panicking.... oh, she is 18 months old