As summer approaches, we all know the days get longer and the temperature and humidity increase. These changes, along with more time outdoors for entertainment and exercise, can promote a variety of health risks.

One is the impact of heat and dehydration. Increased temperature along with brisk trade winds speed up water loss from the skin. It becomes more important to think about adequate fluid intake. Dehydration can trigger a variety of health problems, even headaches in some people.

As a general rule, if your urine starts looking more like apple juice and less like lemonade, you are not drinking enough.

Another risk is food safety. Hidden microscopic food invaders thrive in warmer weather and can make us very sick and even kill people. Summer is a good time to consider how to keep food safe both at home and at special events like picnics and potlucks.

Here are some of the most basic guidelines for keeping food safe:

>> Wash hands thoroughly before preparing foods.

>> Thoroughly clean cutting boards and knives after cutting up raw meats, poultry and fish to avoid cross contamination.

>> When serving buffet style, keep cold foods cold and hot foods hot to minimize the growth of microorganisms. Remember the “two-hour rule”: After two hours at room temperature, the growth of potentially dangerous microorganisms increases exponentially.

>> Handle leftovers carefully. Hot foods that were out for some time should be refrigerated soon and thoroughly reheated before serving later.

By far the greatest food safety risk is from pathogenic bacteria. However, it has become increasingly important to be aware of rat lungworm disease. This disease is caused by a parasitic roundworm most commonly acquired by consuming fresh produce such as lettuce containing one or more small slugs that go unnoticed.

It is called a lungworm because it was first discovered in the lungs of a rat. In people, the parasite travels mainly from the intestines to the brain where it can cause severe damage, horrible pain and even death. In rare cases, the parasite has even moved into the eyes.

The severity of symptoms can vary from relatively mild ones that resolve without treatment to severe headaches, nausea, vomiting and pain throughout the body. Currently, medical treatment of rat lungworm infection is somewhat controversial. Medications that can kill the invader may result in rapidly dying worms whose dead tissues may cause a severe immune reaction in brain tissues and lead to serious problems.

However, some physicians have found that prompt treatment with these worm-killing medications can shorten the duration of symptoms. The best treatment approach may vary from case to case.

To decrease risks, inspect all produce and wash well. Tiny slugs can easily be missed yet still carry the lungworm parasite. If you get symptoms and suspect rat lungworm, get medical attention as soon as possible and tell your doctor that you might have been exposed to rat lungworm.

For more information, visit health.hawaii.gov.

Alan Titchenal, Ph.D., C.N.S., and Joannie Dobbs, Ph.D., C.N.S., are nutritionists in the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa. Dobbs also works with University Health Services.