The Aloe Vera is famous for its many cooling effects and its positive effect on skin. The Guide of Poisonous Plants also states that gel from an aloe vera plant is good for cuts, rashes and burns. But the inside of the leaves also contains latex which can be confused with the gel.
When ingested, this can cause gastrointestinal discomfort including cramps, diarrhoea, vomiting and red coloured urine. Aloe latex can also caused skin irritations.
Fortunately, the plant rarely causes serious or prolonged illness. If you like to be safe, buy an aloe vera based product instead of using the plants for cuts and burns.
Additional Reading on Aloe Vera: Aloe Vera – Fight 80 Disorders from Your Own Kitchen!