On an average you need seven to eight hours of sleep daily. But there can be seasonal and periodical variations in your sleep requirement. During the change of season you need more sleep as the body is trying to adjust to the new set of bacteria and virus in the environment. If you don't take adequate rest you may fall sick and body will take rest forcibly. It is better to take adequate rest as per the needs of your body.. In the mean time ensure adequate nutritious diet and regular exercise. You may do deep breathing exercises and Yoga under supervision.