Solved the problem of being able to do today's session with as little pain as possible ! : (1) Cut the legs off a pair of panty hose, keeping just enough to cover chafed parts; (2) lathered areas with vaseline; (3) carefully put on modified pantyhose & an old pair of thigh length shorts. It worked & managed to do 3km warm up, 5 X 600m reps. with 90 secs intervals, 3km cool down.....on a treadmill at the new gym in Mittagong. Count as 10km.
Not bloody likely to ever let chafing happen again!