Scientists studied how a fungus called Armillaria gallica responds to high heat, which is important because this fungus forms a partnership with a valuable medicinal plant called Gastrodia elata. They compared a heat-tolerant fungal strain with a heat-sensitive one and found that the heat-tolerant strain increases sugar accumulation and activates specific genes that help it survive hot conditions. Adding sucrose to the fungus’s growth medium helped it tolerate heat better, suggesting that sugar plays a key role in heat stress protection.