Recommendation on a heater

[Isawe]

Hello, I was wondering if anyone could recommend a good heater for my budgie's cage. My apartment gets cold in winter, and I want to start preparing.
Since I read most space heaters are bad for them, I would love to know if anyone could help me.
Thank you so much for any advice!! I really appreciate it

Here a pic of my babies!! With a bad feather day after a bath lol

 

[Kassiani]

I have a special needs Conure for whole I use a Sweeter Heater, and the room where the budgies and the Conure sleep also has a DeLonghi radiant oil heater. I “burned off” both in my garage before using them to get rid of the plastic smell.

 

[Pixiebeak]

sweeter heater! I've had one for 20 years

 

[Isawe]

Thank you so much for all the advice and I appreciate every answer, I'm trying to find multiples options for my babies because they don't like to stay in one single spot or like to bite everything