Could Climate Change Make It Too Hot for Humans to Survive?

In a scenario worse than the IPCC's worst case, where all the recoverable fossil fuels are burned, there's a one in six chance we'd see greater than nine degrees Celsius of warming by 2100. And it looks like there's an extremely small, but real, chance that this would be enough to cause the worst case cloud feedback loops discussed above. We'd reach that 13 degrees Celsius in the years or decades after we trigger the cloud feedback tipping point. This could make significant parts of the planet uninhabitable, at least outdoors or without air conditioning, for significant portions of the year. If temperatures rise high enough, it becomes too hot for humans to survive for more than a few hours