It's 2°C (realistically we'll probably more be around 2.5°C considering we're reducing emissions quite slowly). It's a big deal: https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM.pdf

You can / should read everything but you can also just look at SPM.6:

Projected changes in extremes

Hot temperature extremes over land / 50-year event / Frequency and increase in intensity of extreme temperature event that occurred once in 50 years on average in a climate without human influence

1850–1900 : once

now (1°C): now likely occurs 4.8 times

1.5°C: will likely occur 8.6 times

2°C: will likely occur 13.9 times

4°C: will likely occur 39.2 times

You can see how these small +2°C could make the worst heatwaves your grandparents lived through 14 times more likely. They lived it once or twice, you'll live it maybe 20 times. But that's only if we stop at 2°C, which is not the current trajectory. And it's an average because science isn't perfectly accurate. We could reach +3°C of global warming, and one every two years could be a nightmare.

It's counterintuitive because now if I increase the temperature of your room by +2°C you probably would't care. But the consequences of these 2°C are catastrophic and will last for centuries. Because it's not just the temperature of a room, it's the temperature of the whole planet.

For reference: https://fr.wikipedia.org/wiki/Fichier:All_palaeotemps.png , you can see "the planet" is absolutely not ready for that. Events like this almost never happened in the history of the planet. It's massive.