It's getting cold across much of the US, and that means it's a good time to consider the possible winter hazards on your next flight.

1) Hypothermia

As the weather gets colder, most of us start bringing a coat, or some gloves, but it's important to think outside the scope of normal flight operations. What happens if you are forced to make an off-airport landing? What will you do if search and rescue is several hours away?

Think about adding a lightweight emergency blanket to your flight bag. In the winter it can help block wind and retain your body heat. In the summer, your blanket can double as a shade shelter. Hopefully, you won't have to use it, but if you do you'll be glad you packed it.

2) Hypoxia

You've probably been using your airplane's heater for a while now.

Most GA aircraft use a heat exchanger (sometimes called a shroud) around the exhaust manifold of the engine. This shroud uses hot exhaust air to radiate heat to the cold outside air that can then be passed into the cabin.

When working as intended, this is a safe way to keep you comfortable, but if there is damage to the shroud or exhaust manifold, it's possible for exhaust fumes to leak into the heating vent, and then into your cabin.

Carbon monoxide (CO) from the engine exhaust can impair your judgment and motor skills, and in higher doses leave you unconscious. CO does this by binding to the hemoglobin in your blood, preventing oxygen from normally bonding to your hemoglobin.

3) Dehydration

Dehydration is more heavily focused on as a risk during the summer, making it easy to forget about in the winter.

Dry winter weather can make you feel like you don't need to drink as much water, but you do. Dehydration can limit your cognitive performance when you fly. Recognize the symptoms of dehydration:

• Fatigue
• Headaches
• Dizziness
• Confusion
• Extreme thirst

4) Fatigue

Fatigue is a '24/7/365' risk factor. But the gray, cloudy days of winter are a good reason for you to pay even more attention to it.

Shorter and cloudier days can trick your body into thinking that it's time to relax and fall asleep when it isn't. This can come in the form of increased melatonin (sleep hormone) production or seasonal depression.

Fatigue is a risk factor that is particularly dangerous when combined with other risk factors like stress.

So how do you mitigate it? Set boundaries. This winter, revise (or add) a "minimum hours of sleep" to your personal minimums checklist.