This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
In severe heat strain the heat stress index (HIS) is – 
Select and explain. 
A. 10–30, B. 40–60, C. 70–90, D. 100
B: 40–60
Answer: B: 40–60 
Explanation: None