The National Weather Service has extended the Excessive Heat Warning for the Sierra Nevada through Friday 8 PM.
High temperatures in the Yosemite Valley will be around 100 degrees during the afternoon and early evening hours.
Children, the elderly and people with chronic ailments are the most susceptible to heat-related illness. Heat exhaustion, cramps or in extreme cases heat stroke can result from prolonged exposure to these conditions. Pets and livestock are also vulnerable to heat illness and should be cared for properly.
Remember to drink plenty of fluids, stay in an air-conditioned rooom, stay out of the sun, check up on relatives and neighbors who might need assistance and reduce outdoor exposure.