Four volunteer firefighters died this week in forest fires caused by a severe heat wave that has swept Mexico, authorities said. Fires in several states across Mexico have destroyed at least 150,000 hectares (370,500 acres) of forest, jungle and pasture according to official figures. Temperatures have surged to between 40 and 44 degrees Centigrade (104 and 111 degrees Fahrenheit) in the northern states of Coahuila and Tamaulipas, central San Luis Potosi and in southern states such as Campeche, Yucatan and Chiapas.