Most of us welcome hot weather, but when it's too hot, there are health risks. During heatwaves, more people than usual get seriously ill or die. Loss of appetite, poor sleep, constant sense of tiredness, periods of hot weather don’t always agree with us. But along with the usual precautions we should take during heatwaves, food and drink may help us out on ultra-balmy days.
Why is a heatwave a problem?
The main risks posed by a heatwave include, not drinking enough water (dehydration) , overheating, which can make symptoms worse for people who already have problems with their heart or breathing , heat exhaustion and heatstroke.
We typically lose between 2 and 2½ litres of fluid a day through sweating, breathing, urine and faeces. So on regular days we should be drinking about 6-8 glasses of water or other hydrating liquid. Higher temperatures and humidity increase the speed of evaporation from the skin which means we sweat more. Therefore we need to replenish our fluid levels more often and more frequently. Remember caffeinated drinks have a diuretic effect, making you lose fluids, so keep them to a minimum during extreme hot weather.
Foods account for around 20-30% of our fluid intake, and there are some that contain more water than others. Certain fruit and vegetables score highly in this regard, and we should think about eating more of the following if we want to up the H2O:
Recipes with high fluid content can help towards hydration levels. Soups, stews and porridge are all good examples, and of course they can be made less wintery with the right seasonal ingredients.
Ice-cold lollies, slushies and ice cream might seem like natural choices when you want to cool off, but they may actually do more harm than good. Cold food and drinks might give you an initial cooling effect but it’s short-lived because consuming food leads to an increase in temperature as the process of digestion is heat-generating. This combined with the rapid cooling initiated by cold food and drinks means your body over-compensates by increasing your core temperature. So you may actually end up feeling hotter than you did to start with.
Drinking something hot on a sunny day might feel like the least appealing thing to do, but warm drinks can actually help regulate your body temperature. Hot drinks make your core temperature rise and that makes your body want to cool down so you sweat more to lose heat through your skin. ‘Thermogenic’ foods like spices and chilli also increase body temperature as they kick-start our metabolism. This promotes sweating, which has a cooling effect.
Foods we should avoid
Foods that require more effort to digest ,like those high in protein, sugar and fibre are thought to generate more body heat. One way of mitigating this is to use citrus-rich marinades on meat to break down the protein structure and soaking grains to help make the fibre more digestible.
If you don’t feel like eating as much in the summer, you’re not alone. Seasonal changes including temperature and the number of daylight hours are thought to influence our appetite. In the summer our appetite tends to be reduced, especially when we’re feeling hot. One reason for this is that the body tries to regulate our body temperature by cutting down on heat-generating functions like the digestion of food.
While this kind of drop in appetite might be out of our control, we can help ourselves by ensuring the food we do eat is packed with the right nutrients.