Feeling the Heat

When your body gets too warm, it has ways to cool itself down, like sweating. But you can also take voluntary actions, like removing a piece of clothing. That’s called “thermal behavior,” and University at Buffalo research has discovered that when it comes to thermal behavior, there are differences between the sexes.

Why does that matter? It could impact the development of athletic wear. More importantly, it might have clinical applications, particularly, say researchers, in relation to multiple sclerosis.

The researchers, from UB’s School of Public Health and Health Professions, hadn’t planned to look at sex differences in the initial design of the study. But, explained lead author Nicole Vargas, “we began to see some interesting trends that we felt were necessary to follow up on through further data collection and analysis.”

In the redesigned study, male and female participants rode an exercise bike while equipped with a tubing system that allowed them to cool down their neck with a burst of minus 4-degree liquid whenever they felt too warm.

While exercising, the women used more of the cooling liquid than the men—which didn’t come as too much of a surprise to researchers. Women have more subcutaneous fat than men and tend to perceive temperature changes more acutely.

“The really interesting thing we found was during recovery,” said Vargas, noting that women continued to cool themselves for an hour after exercising, despite the fact that their skin temperature returned to normal levels six times faster than the men’s.

Vargas believes this is because their core temperature remained elevated, an indication that core temperature is a crucial component of thermal behavior.

Up to 80% of patients with MS experience heat sensitivity, which can exacerbate symptoms like blurred vision, loss of balance and even cognitive problems. That made researchers wonder: Do people with heat-sensitive MS listen to the thermal signals within their body appropriately? Could better thermal behavior mitigate symptoms?

A study currently underway hopes to answer those questions and pave the way for new clinical applications. “This whole line of thermal behavior research has opened up a lot of doors for us,” said Vargas.