Research highlights the critical relationship between temperature and the immune systems of vertebrates, revealing that each species has an optimal temperature for effective metabolism and disease resistance. While warmer temperatures can enhance immune responses initially, excessive heat favors the growth of pathogens. Cold-blooded animals, such as reptiles and amphibians, are particularly affected, as they depend on environmental temperatures to regulate their body heat. For instance, the chytrid fungus, responsible for significant amphibian declines, thrives in cooler conditions, threatening species like the leopard frog. Innovative solutions, such as 'frog saunas' designed to raise temperatures for infected frogs, are being explored to combat these challenges. As climate change progresses, the range of various pathogens is expected to expand, increasing risks for wildlife. Understanding how temperature influences immunity will be essential for developing conservation strategies to protect vulnerable species in a warming world.