Thanks, man I'm glad I found this forum as I'm beginning to think the bird store that sold me my budgie doesn't know anything as they told me to add the oyster shells to his food. He does have a cuttlebone and mineral block but I haven't seen him chew on them yet, instead he climbs all over them, I think he thinks they're toys!
Yes, there are no drafts around him it's just the thermostat next to him.
Good thinking I will also tell her to help herself to anything in the fridge haha.
Thanks again for the tips!