That image is not accurate. You can easily survive if it happened to be 100 Celcius outside. (but not to long), Infact, many Russain traditional "steam baths" (idk proper english term for them ) have air temperateness above 100C. No one dies because gasses are bad at transferring heat, so even thou it might 100C outside your body temp would still be around 40C  If you touch a 100C solid or liquid, which are better at transferring heat, then you will get injured or killed thou