Non-reinforced hose such as silicone vacuum hose has a max temp rating of 550°F.
Reinforced hoses that are reinforced with Polyester have a max temp rating of 350°F.  This includes most couplers and heater hose.
Reinforced hoses that are reinforced with Aramid have a max temp rating of 550°F.  This includes any coupler that is indicated on our website to be "Extreme Temp".