As shown in this article, we're seeing heatwaves in the 120F range now, with "only" 1C increase in warming. While I can't find any specific estimates in the IPC

As shown in this article, we're seeing heatwaves in the 120F range now, with "only" 1C increase in warming. While I can't find any specific estimates in the IPCC reports (section 2.2 in the full report seems the most relevant section), the report frequently mentions more extreme heatwaves. It doesn't seem radical to me as an uneducated observer to extrapolate that out to 150F with another 2-3C increase, especially in the context of a casual conversation like we're having here.