Bad news Spurs fans ... the team has announced they've fixed the air conditioning system at the AT&T Center ... which means LeBron James might actually play the whole game next time they face off in San Antonio. 

After last night's debacle, temperatures on the court got up to 90 degrees ... and LeBron was carried off the court in pain after complaining of leg cramps. 

But moments ago, the team said maintenance teams had identified and corrected the problem -- which means fresh, cold air will be blowing through the arena when the teams take the court for Game 2 in S.A. on Sunday.