1993 Mazda MX3 V6 5 speed motor runs fine for about 15 minutes then shuts

[oldemovies]

down until completely cooled off.? 1993 Mazda MX3 V6 5 speed motor runs fine for about 15 minutes then shuts down until completely cooled off. Temp gauge never goes above normal. After cool down she starts up and gives another 15 to 20 minutes of service at all ranges of operation. No engine light is on and there is good operation during the start up period.
Thanks