alrighty so its been crazy hot here lately, upwards of 40 degrees C or upwards or 90 F.. and i was parked at a coffee shop this afternoon and suddenly my coolant came barreling out of the overflow container.. so i thought maybe its my thermostat.. so i got a little bit of ice and water, threw it in after turning the car off and then once it was at normal operating temp, i started it again, cranked the heat and drove the piss out of it for 2 minutes.. now its ok and the temp needle is stable. my question is this: should i replace the coolant? should i replace the thermostat? i'm not too worried if i have to do either cause they're both things i can do myself.. any opinions?