I ususally wear wellies all year around, have you tried goloshes or crocks during the summer. Don't have bare feet though choose a light white tainer ankle sock which is cool, but also protects, keep the 20 plus suncream on and take care. Also make sure you divide the work throughout the day and take rests in between. This may help.
Essential Oil Blend. To reduce foot swelling, rub a mixture of plant essential oils to the swollen feet and ankles. Some of the best essential oils for treating swollen feet are eucalyptus oil, peppermint oil, lavender oil, lemon oil, grapefruit oil and rosemary oil.
make sure to stretch too. I would recommend the crocks though as good working material.