clutch sticking

[lachap55]

2010 370z convertible clutch pedal stuck happen right after the warranty ended. happen first time when car was run in lower gear (4TH) without realizing it; and reach temperature just under limp mode. once car cooled down and a few toe pull up, the clutch pedal came back to normal. it happen again just yesterday under the same conditions. if this is an overheating problem; i might don't need to change or look into slave cylinder. i might just need the car engine cooled. here in Florida with temp in the high 90's; just going 70-90 mile open diving sends the temp in the 210-240 range, and has been since i owned the car brand new. 1.get better transmission fluid, 2.16-19 row oil cooler with therm. plate. and 3.change the oil sooner then specs allow. am hoping the transmission fluid gets to hot and causes clutch pedal to stick in those condition. WHAT YA'LL THINK?