Marco Island lends itself to sunbathing on the long white sand beaches. Cooling off generally means a dip in the shallow waters surrounding the island. Just be careful, there are sting rays in them there waters. If one of these normally placid fellers gets you, you,re in for some pain.
Marco's beach sand consists on a large part by broken shells. These can get very sharp. If you are going to do a lot of walking and have tender feet, bring water shoes or sandals.