Is my puppy getting sick because of house temperatures?

Hello, I have a 13 week old Chihuahua puppy and she will be 14 weeks on Monday, the vet said that she had a soft coat, and her ears are cold all the time. She also sneezes a lot but only when her nose gets hit. We usually set our thermostat to 61 to 68 at night to help us sleep better and 61 to 72 during the day, are these temperatures to cold for my puppy?