A recent EPA study found that indoor air pollution may be even more harmful than outdoor pollution.

But there are some ways to protect yourself when you travel.

Major hotel chains like Marriott, Hilton, and Hyatt are now offering clean air hotel rooms, with medical grade air filters, microfiber linens, and sanitized heat and air conditioning. Be prepared to pay about 5%-7% more for your room.

And if your hotel doesn’t offer this service, there are travel size air purifiers on the market. These weigh about a pound and cost an average of $34.