I know it's "just" a comic but I feel obligated to let every reader know that the burnt toast thing is a weird myth.
FAST: Face, Arms, Speech, Time. Check their smile, check if they can hold up both arms, check if they have slurred speech or can speak at all, and call emergency services asap because every second matters. Have them rest peacefully while you wait for help.
There is potentially life saving medication that can even reverse some effects of a stroke, but it is time sensitive.