I have a sweaty 3 week old?

My baby girl is 3 weeks old and sweats alot its summerish temperatures where we live so our thermostat is on 69 (Fahrenheit ) and she can sleep in just a onsie socks and mittns and she'll break a sweat could it be something to do with her glands being overactive or do babies really just get that hot? She's not sick and her temp is normal.