Valetudinarian

I seem to be ill again. I have more than my fair share of sickness. My throat is sore, my bones ache and I'm listless.
It's undoubtedly nothing more than a cold, yet I don't understand why I get them all the time. I'm not skipping meals and living solely off crisps anymore (sadly), I can run 4km in around 18 minutes at the gym (though my times have lessened off lately as I haven't been going as much), and I'm getting more sleep than usual.
I must have a low constitution - one so low that I'm getting deductions on my hit points rolls.
All it takes is one weekend at a festival, or one trip out of the house wearing just a t-shirt and I have germs invading my oesophagus.
I'm the only man in the world capable of catching a cold just by looking at a picture of a polar bear.