You're right. 180 would produce no acute results and a very small chance of somatic results. Here's my thoughts. Semi tropical atmosphere, no electricity, worked to the bone, stress,
Lets see the effects of heat exhaustion :
Symptoms of heat exhaustion include profuse sweating, weakness, nausea, vomiting, headache, lightheadedness, and muscle cramps.
Effects of sleep deprivation :
aching muscles, confusion, memory lapses or loss, depression, hallucinations, hand tremors, headaches,
bloodshot eyes
Why radiation then? Easy answer : its there. Its a good scape goat, and something media fear mongers like that quack Dr. Kookoo (sic) can quickly resort to when asked.