Resealable bottles for beverages. A bottle may include a main body with an opening for receiving contents and a reservoir for storing contents, a lid, and a bottom, which is interchangeable with an accessory for changing a characteristic of the contents. The lid may close the bottle and/or facilitate consumption of its contents. The bottle may support one or more indicators, such as LEDs, including a safety indicator that is configured to activate when the safety system is active and the resealable bottle enters an unsafe state. The accessory may provide, for example, heating and/or cooling.