Peel the jicama, including the fibrous layer just beneath the skin. Thinly slice the flesh and then cut into thin 1 inch strips. Place in a bowl. Working over a bowl to catch the juices, peel the oranges and cut between the membranes to remove the sections. Remove the seeds. Transfer the orange sections and juice to the bowl with jicama. Peel and core the pineapple, and trim out any eyes, being careful to save the juice. Cut the pineapple into 1 x 1/8 inch strips and add to the jicama bowl along with the juice. Add the red onion, habanero chile or cayenne pepper, lime juice and salt. Toss well and chill for 30 minutes. Serve cold.