A foam pad under the basket will supply a softer ride and you will have no hang-ups in the slush. An injured person enclosed under a zippered cover tends to become claustrophobic, also there is a danger of carbon dioxide gases being trapped under the cover. Yes, all rescue transportation should have an attendant riding with the injured person. A serious problem may arise which may need immediate attention. Be sure the rescue vehicle has accommodations for the attendant.
Rescue teams are always prepared with soft light blankets.
Be sure the injured person is well covered. Loosely around the face. Stop often, shock can develop at any time. The recommended speed is approximately 10 mph. Any faster will jeopardize the patient and the attendant.