In the hot months, using a wool diaper cover may seem counter-intuitive. However, wool is a great temperature regulator.
“Wool’s scaling and crimp make it easier to spin the fleece by helping the individual fibers attach to each other, so they stay together. Because of the crimp, wool fabrics have greater bulk than other textiles, and they hold air, which causes the fabric to retain heat. Insulation works both ways: Bedouins and Tuaregs use wool clothes to keep heat out and protect the body.” -via Wikipedia
For those living in extremely hot climates that are trying to avoid synthetic (PUL or plastic) covers, I would recommend using a diaper without a cover whenever possible. Change baby when the outer layer of her diaper is damp.
There will be times when baby needs to have a cover on. Don’t put clothes over their cover: use the wool cover as their shorts. This will allow for maximum evaporation and temperature regulation by the cover.
Wool shorts or “shorties” are another good solution that allow for more air flow between the diaper and cover. You can order them with an extra layer through the wet zone so they are more bulletproof.
Once you have your diaper covers sorted out, I recommend adorable tank tops. This is because it is imperative to show off your baby’s arm rolls for as many months as humanly possible.