BROOKLYN - Exhaustion can develop after several days of exposure to high temperatures and lack of fluids.Those most prone to heat exhaustion are senior citizens, people with high blood pressure and those who are working or exercising outside. Warning signs of heat exhaustion include: Heavy sweating, paleness, muscle cramps, fatigue, dizziness, nausea, vomiting and fainting. Effective cooling measures include: Cold, non-alcoholic beverages, rest, a cool shower, an air-conditioned environment and wearing lightweight clothing.