I have a well established dutchmans pipe plant (10 years old and three stories high). During a recent heatwave all leaves wilted
and dried up completely. Is the plant dead? This happened in July.
It is just likely injured from the heat. If you prune lightly, and take off any fully dead growth, it will likely recover. Just care for it as usual until it recovers. This article will give you more information on the care of these: https://www.gardeningknowhow.com/ornamental/vines/dutchmans-pipe/growing-dutchmans-pipe-vine.htm