You must disclose at the time of booking any medical condition that could affect your ability to do the trek in Vietnam. Hiking Vietnam reserves the right not to accept a trek booking if we feel that a medical condition may put your life or the lives of any of our trekking staff or other clients at risk on the trek. People with heart conditions, knee problems, severe asthma or are more than 18 weeks pregnant should not participate in the trek. People with mild asthma / diabetes / pregnant less than 18 weeks will have to bring a medical note from their doctor stating that they are fit to undertake the trek. They will also be required to be accompanied by a trekking companion on the trek at all times who will trek at their sides and be familiar with any medicines required in case of an emergency. Hiking Vietnam reserved the right to cancel the trek booking of a client if the client has not fully disclosed at the time of making a booking a medical condition that may pose a risk to the health of the client and/or other hikers. No refunds will be given in this instance.