Patient monitoring is becoming a requirement for offering a better healthcare to an increasing number of patients in nursing homes and hospitals. During the monitoring, vital signs of patients could fluctuate significantly and/or match certain undesirable patterns and therefore "alerts" or emergency messages must be delivered to healthcare professionals. There has been some work in using infrastructure-oriented wireless networks for transmission of emergency messages, however, the network coverage and reliability of message delivery have not been satisfactory. To overcome these, we propose that ad hoc networks can be formed among patients? devices for improved transmission of emergency messages. We also propose several design enhancements to improve the quality and coverage of patient monitoring. The performance results for the proposed ad hoc network based architecture show that reliable message delivery and low monitoring delays can be achieved by using multicast or broadcast-based routing schemes.