Hyperthermia means a body temperature that is higher than normal. High body temperatures are often caused by illnesses, such as fever or heat stroke. But hyperthermia can also refer to heat treatment the carefully controlled use of heat for medical purposes. Here, we will focus on how heat is used to treat cancer.
When cells in the body are exposed to higher than normal temperatures, changes take place inside the cells. Warmer temperatures can make the cells more likely to be affected by other treatments such as radiation therapy or chemotherapy. Very high temperatures can kill cancer cells outright, but they also can injure or kill normal cells and tissues. This is why hyperthermia must be carefully controlled and should be done by doctors who are experienced in using it.
The idea of using heat to treat cancer has been around for some time, but early attempts had mixed results. For instance, it was hard to maintain the right temperature in the right area while limiting the effects on other parts of the body. But today, newer tools allow better control and more precise delivery of heat, and hyperthermia is being used (or studied for use) against many types of cancer.
Regardless of extreme weather conditions, the healthy human body keeps a steady temperature of 98.6 degrees Fahrenheit.
In hot weather or during vigorous activity, the body perspires. As this perspiration evaporates from the skin, the body is cooled.
If challenged by long periods of intense heat, the body may lose its ability to respond efficiently. When this occurs, a person may experience hyperthermia. In other words, hyperthermia occurs when body metabolic heat production or environmental heat load exceeds normal heat loss capacity or when there is impaired heat loss.
Symptoms of hyperthermia, or heat-related illness, vary according to the specific type of illness. The most severe form of hyperthermia is heat stroke. This happens when the body is no longer able to regulate its internal temperature; this is a medical emergency. The body temperature may be over 105 F, a level that damages the brain and other organs. Other symptoms include muscle cramps, fatigue, dizziness, headache, nausea, vomiting, and weakness. The heart rate may be elevated, and the skin is reddened. The skin may be moist if sweating is still occurring, or it may be dry if sweating has stopped. Confusion and mental changes may develop, and seizures can occur with brain damage. Ultimately, coma and death may ensue.
Heat exhaustion is a less severe form of hyperthermia. People with heat exhaustion typically experience weakness, nausea, vomiting, headache, muscle cramps, and profuse sweating. Other forms of heat illness include heat cramps, which are involuntary spasms of large muscle groups, and heat syncope, which is fainting or lightheadedness. Heat rash is characterized by a prickly or itchy feeling of the skin coupled with red bumps on the skin.
If the victim is exhibiting signs of heat stroke, emergency assistance should be sought immediately. Without medical attention, heat stroke can be deadly.
Heat exhaustion may be treated in several ways:
- get the victim out of the sun into a cool place, preferably one that is air conditioned
- offer fluids but avoid alcohol and caffeine – water and fruit juices are best
- encourage the individual to shower and bathe, or sponge off with cool water
- urge the person to lie down and rest, preferably in a cool place