Heat and young children
A further complicating factor that coaches of young players must consider is the age of their athletes. As general rule children don’t sweat as much as adults and have greater trouble dissipating heat in hot, humid conditions.
Before puberty children don’t have well developed heat regulation systems and are much more susceptible to heat illness than adults.
Greater care needs to be taken with young athletes on hot, humid days. Consider options like:
Understanding heat regulation
- more rest
- reduced playing time
- avoid training in the middle of the day
- competition cancellation (if extreme).
One of the by-products of movement is the production of heat. The human body has some very effective means of dispersing heat to the surrounding environment allowing us to maintain our core body temperature within the narrow band required for good health.
At the beginning of exercise, the additional heat produced by exercising muscles may be beneficial to performance (hence the importance of the “warm up” before competing).
However, if heat continues to be produced more quickly that it can be dispersed, the core temperature of the body will rise and performance will suffer. In extreme cases this can result in heat stroke and the athlete’s health will be at risk.
The two most important ways to cool the body are:
To remove heat from the body, the blood vessels close to the skin open up and an increased supply of blood is sent to these vessels (hence the phenomenon of a flushed face). The surrounding air then absorbs this heat from the skin surface (convection).
This mechanism is most effective when there is a continual flow of fresh air across the body and when the air temperature is below the temperature of the skin. In other words on a hot, still day this mechanism will be less effective.
The second thing that happens is we sweat. The moisture released onto the skin surface absorbs heat as it evaporates. This is more effective when there is low humidity and a flow of air across the body.
When the conditions are hot and humid the athlete’s body will increase its efforts to lose heat by sweating more and sending a greater proportion of the blood flow to the superficial blood vessels under the skin. This has several implications for coaches:
1. It is impossible for an athlete to maintain the same workload, as they would in cooler conditions, for the same length of time because the skin and the muscles are both “competing” for adequate blood flow. Coaches will need to give their players more opportunities to rest and recover during competition and training sessions (e.g. more frequent rotations to the bench, more frequent breaks during training).
2. There is a risk of dehydration as the body continues to produce sweat at high rates. This means it is important athletes are well hydrated before competing and have ample opportunity for fluid intake during competition.
1. Heat Edema
Heat edema is a mild heat illness characterized by the swelling of hands and feet after prolonged exercise in heat. The core body temperature is usually normal.
2. Heat Rash
Heat rash (sometimes called prickly heat) is a skin irritation that occurs when the sweat ducts become clogged and prevent the release of sweat onto the skin. Once trapped, the sweat causes a mild inflammation and an itchy rash that is generally seen in sweaty areas underneath clothing. Core body is usually not affected by heat rash.
3. Heat Syncope
The signs and symptoms of heat syncope include dizziness and/or fainting; an athlete may also experience weakness. Heat syncope is a posture-related event, and athletes recover immediately after lying down with his or her feet elevated. Heat syncope is seen in athletes who are insufficiently acclimated to heat, and who become dehydrated. Unlike other serious heat illness, athletes with heat syncope have a normal core body temperature and recover quickly once they are fully hydrated.
4. Heat Cramps
The signs and symptoms of heat cramps include painful muscle contractions that are associated with dehydration and electrolyte loss after exercising in the heat. An athlete's core body temperature will likely be elevated, but will not be over 104°F (40°C).
Moderate Heat Illness
5. Heat Exhaustion
Heat exhaustion is considered a moderate heat illness that requires immediate attention. The signs and symptoms of heat exhaustion include an elevated core body temperature in the range of 98.6°F - 104°F (37°C – 40°C). An athlete will complain of dizziness, fatigue, headache and occasionally will experience nausea or vomiting. The skin is usually flushed and sweaty but it may be cold or clammy.
Severe Heat Illness
6. Heat Stroke
Heat stroke is considered the most severe heat illness. An athlete with heat stroke has a core body temperature over 104°F (40°C) and appears confused and disoriented. As heat stroke progresses loss of consciousness may occur. With heat stroke, many patients will stop sweating. Athletes, however, generally suffer from exertional heat stroke, in which they continue to sweat. This is a medical emergency.
Back to Physical Therapy