The cause of multiple chemical sensitivity is not known, but it's a problem that affects a growing number of people. Symptoms like headache, fatigue, dizziness, and nausea are usually are triggered when someone with MCS is exposed to certain chemicals. The innkeepers at these MCS-aware B&Bs have tried to make their accommodations suitable for guests with multiple chemical sensitivity and other environmental sensitivities. Cleaning is usually done without chemicals, there are no air fresheners or scented candles, and pillows and linens are usually hypo-allergenic. If you have MCS, you should always talk to the innkeepers in some detail before making a reservation.