Staying inside may protect you from weather, but it may also be bad for your health. The air in our homes, schools, offices and other indoor spaces can be 2 to 5 times as polluted as outside air and in some cases 100 times as polluted, according to the Environmental Protection Agency.

While we usually can't see or smell the pollution, that doesn't mean we don't feel it. People often report having discomfort and building-related health symptoms and illnesses.

Here are steps you can take to protect yourself from unclean air while indoors. Since this is where most people spend up to 90 percent of their time, it's worth the effort to make these small changes to reduce exposure.

1. Air it out

Vent bathrooms, kitchen and laundry room vents to the outside of your house. To prevent polluted air from staying inside, use energy efficient fans.

2. Flue it the right way

Be sure to properly vent fireplaces to keep smoke out of your home.

3. Remember your laundry

Be sure to vent clothes dryers to the outdoors, too. 

4. Keep track of suction

Don't place furnaces, air conditioners or ductwork in garages or any other spaces where they could draw contaminants inside the house.

5. Pack up toxic items

Store paints, solvents, cleaners and pesticides outside of your living spaces.

6. Keep flames outdoors

Don't use candles, cigarettes, vent-free heaters or barbeques inside the home.

7. Test the windows

Make sure windows aren't stuck or sealed shut throughout your house in case you need to air out fumes from crafting activities, housecleaning supplies, or other sources.

8. Heat with care

Choose your water heaters and furnaces wisely. Use sealed-combustion, power-vented or condensing appliances over natural-draft heaters and furnaces. If you have to use a natural-draft appliance, make sure it’s tested for proper venting, and make sure it's located outside of your living spaces.

9. Filter thoroughly

Put a filter or air cleaner in your air conditioning and heating system to keep dirt out of the air and off your ductwork.

10. Welcome in some fresh air

Use whole-house mechanical ventilation to make sure some outdoor air gets into your house.