Virgin ran his 14:14.6 against the Russians on July 28, 1972. He's always claimed the temperature on the track at the time was 106 (I wasn't there but I have no reason to doubt him). The race was run in mid-afternoon because it was broadcast live on "CBS Sports Spectacular". www.weatherunderground.com archives for that date say the high temperature in Sacramento was 100, so Virgin may have been right.
Anyhow, nice to be giving you boys a Craig Virgin history lesson. If there's any other Chris Derrick hyperbole you'd like me to smack down, I'm the one to ask.