It's also natural for football teams when they travel from two or three time zones to the Eastern time zone to experience a touch of fatigue.
An undefeated UCLA team had its national championship hopes dashed by a loss at three-loss Miami in 1998.
Even USC has had its troubles. In 1982, a Marcus Allen-led Southern Cal team lost at 8-4 Florida. A terrific Trojan team in 1979 won a tight one at 6-5 LSU, and in 1974, the co-national champion Trojans lost at Arkansas.
Florida State lost 14-7 at Southern Cal in 1997 but routed the Trojans 30-10 in Tallahassee the next year.
The Vols are 4-1 in Knoxville against Washington State, including a win by the unranked Vols against the No. 17 Cougars in 1994.
Tennessee is 0-4 all-time against Southern Cal. The Trojans have outscored UT 82-7 in California but in the only game in Knoxville, USC eked out a 20-17 win.
California has made eight trips to SEC country with a 1-7 record. The Bears lost to Alabama 66-0 in 1973. The lone victory was at Tennessee in 1977. UT got revenge in 1987. In recent years, Cal lost at Louisiana Tech and beat Southern Miss by 10, a close call that cost the Bears a BCS berth.
Cal's offensive coordinator Mike Dunbar was asked if he has any concerns about playing in the heat and humidity in Knoxville.
``Yes, without a doubt,'' Dunbar said. ``We've made a real effort to be conscious of that. It's a little cooler (here) and not near the humidity. It's hard to simulate. We hope it's one of those cool, 85-degree evenings with 70 percent humidity, instead of 90, 90.''
Dunbar said Cal will hydrate its players as best it can.
``Hopefully, we can fly in, play well and get out of there,'' Dunbar said.
VOLS STRUGGLE VS. TOP 10 IN OPENERS
Cal comes into ranked No. 9 in the AP poll, and that's a bad sign for Tennessee.
The Vols have opened the season against a top-10 team seven times in school history. They are 1-4-2 in those contests.
The only win was over No. 3 Auburn in 1959.
In the last two such matchups, the Vols tied - Colorado in 1990 and UCLA in 1985.
The defeats were to Georgia in 1981, UCLA in 1978, UCLA in 1967, and Auburn in 1958.