Shower temp.

Most of the faucets today are Pressure & Temperature balanced. They use a cartridge that balances water as it flows through it. I suspect that cartridge needs to be replaced. It is a common problem. If you are a bit handy and have basic tools, you can do it yourself. If not, call a local plumber to replace it for you. Hope that helps

Milo

Please tell the brand and the model number of your faucet, Thanks.

John