If your Embr Wave has been updated to the latest firmware (v31 or later), you can simply press once on the warming or cooling side of the light bar (after waking up your Embr Wave) to restart a session with your last used settings!
For example, let's say you used your Embr Wave for cooling and set the temperature to -11 degrees. The next time you want to use cooling, all you have to do is click the light bar once to wake up your Embr Wave and then click once on the cooling/blue side to go back to -11 degrees—no need to ramp down the temperature again.
If you do not have this update, just pair your Embr Wave to the Embr Wave app. Once the app has finished updating the firmware, you'll be able to use this feature!