bmw 518! e34 temp gage rise to red after warmup, heater not blowing hot air?

[skunk9992000]

ok so my car after a few minutes driving, the temp gage goes into the red, and the cars heater is blowing out cold air, engine is hot but not steaming hot so dont think its the head gasket blown, could it be the thermostat, thanks

 

[tpr_inc]

Your thermostat is stuck closed or you're low on coolant.