As reported by The Hartford Courant, May 17, 2004.

Really Feeling the Heat

Why It's Better If Summer Waits

By Kathleen Megan

"It's too hot." While shivering in mid-February, that complaint was unthinkable. It would never be hot enough. But when temperatures hit 90 last week, there were those of us who complained. It was too hot, too soon. We weren't ready.

Dr. Michael Grey, a professor of clinical medicine at the University of Connecticut School of Medicine, says there are plenty of physiological reasons that explain why it can be tough to go suddenly from the 50s to the 80s and 90s.

Most important, he said, is that it simply takes time for various organs - chiefly the kidneys - to adjust to the heat. "The kidneys are the biggest regulatory organ in regards to the heat," said Grey. "Everyone is familiar with the kidney as a filtering organ. It's also critical in salt and water regulation and the regulation of pH in the blood."

When it suddenly gets hot, you are likely to lose fluids and salt, and the kidneys need to adjust, retaining more water or salt from the urine.

The hypothalamus - the thermostat of the body and the part of the brain that signals thirst - is also key to the adjustment to warmer weather. In older people, the hypothalamus loses its sensitivity to change. Thus, a person is less likely to realize that he or she is becoming dehydrated.

"Whenever the temperature goes up, and we are losing more water than we normally do, we need to replace that," said Grey.

If you feel lousy on a very hot day, chances are you are mildly dehydrated, Grey said, and should start drinking water. This is particularly so, of course, if it is humid and you have been exercising.

How long will it take to adjust to warm weather? It all depends on your health, age and fitness, but generally about 7 to 10 days, he said.

But you know New England. As soon as you get acclimated to the heat, the temperature will probably plunge again.