Yes, you can carry limited amounts of dry ice, but only if used in packaging to keep perishables frozen.
Dry ice is a hazardous chemical and there are restrictions on carriage to prevent harm to persons, property or the plane.
You will be asked to relinquish all dangerous or prohibited items found in your carry-on luggage. If you refuse:
AvSec x-ray bags going onto aircraft to ensure there is nothing dangerous in them. If something comes up on the x-ray that needs checking, the bag will be opened, searched and any dangerous good or prohibited item will be removed, with a bag search notification form left within the bag.