Roadbike with aluminium wheels in mountains. Is it safe?
When people talk about blowouts from braking heat, they're usually referring to latex tubes being used with rim-brake carbon clincher wheels. This combination can indeed lead to blowouts on long, fast descents if you aren't careful. I used to run latex tubes with my carbon race wheels, but after having two tube blowouts, I switched back to traditional butyl tubes and never had the issue again. If you're concerned about heat, just ensure that you're using butyl tubes, not latex.