Lactose intolerance is different from a milk allergy. Management is typically by decreasing the amount of lactose in the diet, taking lactase supplements, or treating the underlying disease. People are able to drink at least one cup of milk without developing symptoms, with greater amounts tolerated if drunk with a meal or throughout the day.Worldwide, around 65% of adults are affected by lactose malabsorption. Other mammals usually lose the ability to digest lactose after weaning and this was the ancestral state of all humans before the recent evolution of lactase persistence, which extends lactose tolerance into adulthood. Lactase persistence evolved in several populations independently, probably as an adaptation to the domestication of dairy animals around 10,000 years ago. Today the prevalence of lactose tolerance varies widely between regions and ethnic groups. The ability to digest lactose is most common in people of European descent, and to a lesser extent in parts of the Middle East and Africa. Traditional food cultures reflect local variations in tolerance and historically many societies have adapted to low levels of tolerance by making dairy products that contain less lactose than fresh milk. The medicalization of lactose intolerance as a disorder has been attributed to biases in research history, since most early studies were conducted amongst populations which are normally tolerant, as well as the cultural and economic importance of milk in countries such as the United States. Terminology
Lactose intolerance primarily refers to a syndrome with one or more symptoms upon the consumption of food substances containing lactose sugar.
Heat cramps, a type of heat illness, are muscle spasms that result from loss of large amount of salt and water through exercise. Heat cramps are associated with cramping in the abdomen, arms and calves. This can be caused by inadequate consumption of fluids or electrolytes. Heavy sweating causes heat cramps, especially when the water is replaced without also replacing salt or potassium.Although heat cramps can be quite painful, they usually dont result in permanent damage, though they can be a symptom of heat stroke or heat exhaustion. Heat cramps can indicate a more severe problem in someone with heart disease or if they last for longer than an hour.In order to prevent them, one may drink electrolyte solutions such as sports drinks during exercise or strenuous work or eat potassium-rich foods like bananas and apples. When heat cramps occur, the affected person should avoid strenuous work and exercise for several hours to allow for recovery. See also
Dehydration

References
External links
Heat cramps first aid