This 'dry' Bodycool vest is a non-wet undercoat that provides a lot of cooling on the road. The main difference with other cooling vests is that the Bodycool Dry keeps the necessary water inside.
You do not immerse this vest in water, you fill it. For that reason, there is an opening in the neck. Just hold it under the tap, put it on and you are basically done. Without getting wet yourself.
The physical principle is the same as for all such vests: evaporation and air circulation result in a cooling effect. Thanks to the filling function, this vest has a slightly different cut than the ones you submerge, and you can put a camelbag in your back.
This 'dry’ Bodycool vest is not a full-fledged motorcycle jacket! Above it, you should always wear a ventilated motorcycle jacket. ‘Ventilated' is not a must, but if you know that the temperature of the wearer and of the air will evaporate the water in the Bodycool Dry through the outer wall of the jacket, you understand that there is a need for airflow to remove the water vapor.