Got a cold? Then don’t fly!
A cold may seem like a fairly mundane illness and it mostly has little effect on you aside from a blocked nose and ears but once you get up to altitude it can wreck all manner of pain on you when you begin descending again. If you’re flying amongst mountains and clouds trying to get into a tight valley to land, high rates of descent are often required which will cause some major pain and can very easily puncture an eardrum.
Aside from the physical symptoms, your body will be using energy to fight off the cold virus. That’s why you tend to feel a little more tired than usual when you have a cold. This can reduce your mental capability to some extent which could cause to you to make some bad decisions whilst out flying.
I love flying and I hate having to sit on the ground whilst others go out and have all the fun but there’s almost never a reason to go flying with a cold. It’s very easy to convince yourself “it’s just a bit of the sniffles, I’ll be fine” but for the sake of grounding yourself for a few days why take the risk?