I need 27" monitors that run cool?

I have a 2015 Retina iMac and I run two Dell U2711 monitors (running at 2560x1440) as well for a total of three displays. My iMac runs pretty cool and I love it but the Dell monitors run VERY hot and it heats up my office a full 10-15 degrees compared to the rest of my house. I want to replace the monitors with ones that run SIGNIFICANTLY cooler - preferably ones that will run at the 3200x1800 resolution of the iMac.

Anyone here run a similar setup? Any advice on monitors I'd be happy with?