Cold weather

• Wear several layers, including gloves and a hat. Remove layers when you warm up, and replace them during the slower portions of your workout.
• If it is snowing or icy, be extra careful to not fall.
• Remember, you can still become dehydrated in cold weather -- so you still need plenty of fluid before, during, and after exercise.

Hot weather

• Wear light-colored, lightweight clothing.
• Drink plenty of water before, during, and after you exercise. This is important at all times of the year, but especially when exercising in warm weather.
• Take it slow, and be cautious about pushing your limits. Don't push yourself too hard, especially in the heat. Remember that you still need to replenish fluid even when you don't feel thirsty. If you do feel dizzy, lightheaded, or sluggish -- stop, rest, and drink some water immediately!
• Heat stroke is a medical emergency. It may decrease your level of consciousness or even cause a seizure. If you experience more serious symptoms -- such as nausea, headache, confusion, clamminess, trouble focusing, fever, or sudden lack of sweating -- you should go to the hospital right away. You should also see a doctor promptly if your heavy breathing, dizziness, and excessive fatigue remain after you have rested and drank water.
• If heat, humidity, or pollution make exercise too hard, exercise indoors or during cooler hours.