Valerie has these signs: extreme fatigue, dizziness, nausea, vomiting, fainting, and a weak, rapid pulse. these are telltale signs that valerie is suffering from

Answer;
These are telltale signs that Valerie is suffering from Heat exhaustion. 

Explanation; 
Heat exhaustion is a part of heat related illnesses that begin with heat cramps, progresses to heat exhaustion, and finally to heat stroke. 
The body cools itself by heavy sweating and allowing that sweat to evaporate.
Heat exhaustion symptoms include excessive thirst, headache, weakness, nausea, vomiting, dizziness, muscle cramps and a weak, rapid pulse.