I can smell "sick".
Sounds crazy I know. But I swear I have been able to smell strep or a bronchial infection every time. There's something in their breath or their smell when they talk or whisper to me up close.. It's different and I can't explain it. Strep smells a certain way. Almost like chemical or metal. Lung infection smells like... Well green boogers.
I've known immediately when they've had either if these and been right every time. Weird I know. Not a sixth sense. I can actually smell it. Not sense it.