A 58-year-old Puerto de la Cruz man died yesterday lunchtime after suffering a cardiac arrest while walking sendero 6 in the Pico Viejo area of the Teide National Park. Emergency services say that they were called out around midday with reports that the man had collapsed but that sadly medical crew attending could not help him and he was declared dead at the scene.
It does appear that this man had a pre-existing condition, and so it is worth reiterating that Teide is a staggering 3,718m high, making it the highest point in Spain and the third highest volcano in the world. The caldera, and indeed the national park generally, has an average altitude of over 2,000m. Atmospheric changes which can cause altitude sickness start at around 2,500m but apart from altitude sickness itself, these changes can cause problems for those suffering heart and lung conditions who can begin to experience repercussions at lower altitudes.
People with such conditions are generally well advised not to go above the level of the caldera, and so should not go up in the cable car, nor try to ascend the peak of Teide itself. Those with severe heart or lung conditions would be well advised not actually to go even as high as the caldera itself.