News Plants On hot summer days, this thistle is somehow cool to the touch The flowers of this yellow thistle stay cool even as the air scorches around them In southern Spain, summer heat can make life tough for a plant. The thistle Carlina corymbosa beats the heat by somehow cooling down its flowers to well below air temperature. Carlos Herrera Share this:EmailFacebookTwitterPinterestPocketRedditPrint By Darren Incorvaia February 26, 2024 at 11:00 am In the mountains of southern Spain, one type of thistle plant seems to have built-in air conditioning.