In general, if you can avoid ambulance, it is better to drive yourself i.e. if patient has a broken bone, burn etc BUT if severe loss of blood or heart attack call an ambulance as their teams can do CPR.
1. The General Emergency number for ambulances is 1990.
2. T&T has also found the Medi Help service to be useful. they are a subscription based service that you can register for. They have doctors and ambulances available 24/7. Their numbers are 0112 375 888 and 0714 200 095.