2002 Toyota 4Runner Shifting problems when cold

2002 Toyota 4runner automatic, V6, 3.4L, with 150,000 miles - transmission won't shift from 1st to 2nd gear until driving car for about 1 mile. The RPMs increase when pushing on gas pedal but transmission won't shift. Problem occurs when the outdoor temperature is below about 50 deg.F. Same problem occurs after car is driven and sits for about 6 hours in 50 deg. or less weather. After warm up period, problem goes away. Transmission fluid and spark plugs were replaced at 120,000 miles. However, problem existed before this work was done.

Any advice would be greatly appreciated.
Thanks!