ISB Health Clinic: Staying Hydrated

By: ISB Health Clinic
nurse@isb.ac.th

As we enter into the hot season in Bangkok, we all need to make sure we are drinking enough fluids to make sure we remain healthy. If we allow ourselves to get dehydrated we increase our risk of heat related illness (which can be fatal if not treated appropriately).

How much should we drink?
Adequate daily intake will depend on age, sex, environment and activity.

Age and sex
Recommended intake for males and females in temperate environment:

*The required intake will increase with hotter/more humid environmental conditions and exercise.

Environment
Increasing the environmental temperature and humidity will increase fluid loss through sweating. Therefore the recommended daily fluid intake will increase. With high humidity there is still significant loss through sweating but no decrease in body temperature from evaporation of the sweat.

Exercise
When we exercise we increase fluid loss through sweating and increased respiratory losses. Therefore the longer we exercise the more we need to increase our fluid intake. With excessive sweating care must be taken to replace electrolyte loss not just fluid loss.

At ISB we monitor the ambient temperature and humidity to determine the “Heat Index”. As the heat index increases the amount of time students are outside exercising is decreased and rest time increased to try and prevent excess fluid loss.

Effects of inadequate fluid intake

• Headaches. Dehydration will cause headaches in many people and is a known trigger for migraines in some people.
• Low blood pressure. This may lead to “fainting episodes” and dizziness.
• Constipation. When the body becomes dehydrated it does everything it can to conserve water. This included taking water from the bowel motions which can cause very hard motions which the bowels have trouble passing. Constipation can cause quite severe abdominal pains.
• Kidney stones. As the body tries to stay hydrated it produces less urine which is more concentrated with the body’s wastes. Some of these wastes can form kidney stones due to the fact they are so concentrated.
• Urine infections. Due to the fact we produce less urine when we have inadequate intake we are at increased risk of urine infections because we are not regularly emptying our bladders
• Mental impairment. Even with only mild dehydration there is a reduction in concentration and mental performance.
• Substantial increased risk of health related illness. Inadequate fluid intake increases the risk of heat related illness which can be life threatening if not recognised and treated appropriately. It is important that we are adequately hydrated before we start any exercise (or even be outside for prolonged periods). Fluids should be consumed throughout the day not just immediately before exercise (where it is still in the stomach being absorbed).

What should we drink?
Generally water is the best fluid to drink to remain hydrated. At ISB students are encouraged to carry water bottles with water in them at all times.

Sports drinks and electrolyte replacement drinks do have a role with electrolyte replacement in those who have been sweating a lot from intense physical activity lasting an hour or more.

Fruit juices and soda should be avoided due the the sugar content which may actually cause dehydration (by drawing fluids into the gut).

Alcohol and caffeinated drinks should also be avoided.

How do we know if our intake is adequate?
Our intake is adequate if we are feeling well, passing urine frequently (at least every 3 hours) and our urine is pale in color.

In the student bathrooms at ISB we have a “Urine Chart” which encourages students to look at the color of their urine to see if it shows they are adequately hydrated (and encourages them to drink more if they are not).

Teaching staff are encouraged to frequently remind students to drink their water and PE staff give students regular water breaks throughout the class.

How can you help?
Discuss with your family the importance of adequate fluid intake.

Ask your child how many times they have gone to the toilet during the day and what color their urine is.

Measure the volume in your child’s water bottle and tell them how many times they should fill up their water bottle during the day. For example if they have a 250mL water bottle and they are a 13 year old boy they should be filling it up 6 times in a 24 hour period (to get to 1.5 liters) (they need more if they are outside and exercising). At the end of the day ask then how many times they have filled it up. In the clinic when we ask students how often they fill up their bottles most of them say they never need to fill them up.

Ensure you have adequate fluids yourselves. Our children often model their behaviour on what they see us do!

What are we doing at ISB?

• At ISB we are monitoring the ambient temperature and humidity to determine the “Heat Index”. As the heat index increases the amount of time students are outside exercising is decreased and rest time increased to try and prevent excess fluid loss. If the Heat Index gets too high outdoor activities are suspended.
• ISB students are encouraged to carry water bottles with water in them at all times.
• In the student bathrooms at ISB we have a “Urine Chart” which encourages students to look at the color of their urine to see if it shows they are adequately hydrated (and encourages them to drink more if they are not).
• Physical Education teachers and athletics coaches are carefully monitoring students, ensuring sufficient water and rest breaks, and advising students about the need to remain hydrated.
• ES teachers are informing students to drink water before and after lunch, recess and PE – as well as throughout the day
• All teaching staff are aware of heat related illnesses to ensure it is recognised early and treated. If staff are concerned that a student may be suffering from a heat related illness he/she is referred immediately to the Health Clinic.
• PE teachers and after school athletics coaches are coordinating to identify students in sequential physical activities to ensure greater monitoring, rest and hydration take place.

ISB is committed to your child’s overall development, both educationally and health related. Should you have any questions or concerns, please contact your healthcare provider or the ISB Health Clinic (nurse@isb.ac.th).