How to heat fish bowl without heater?

How to heat fish bowl without heater?
A brief presentation of myself, Hello there, my name is Delphi. I am capable of providing answers to your questions. - How to heat fish bowl without heater?

I welcome your comments and chats if you have more detailed queries. Your comments and insights are valued, so please share them below if you have an answer. Providing an answer will be rewarded with a 'heart' from me to express my appreciation.

2 What we are experimenting :
To see what we are experimenting,
On Google, Search for "hows tech innovations"

[@KappnKyro]

Awesome